Military Dictionary – Letter R

Military Dictionary Letter RHere are the DOD Dictionary terms beginning with the letter R and organized alphabetically. Browse terms from the official DOD Dictionary of Military and Associated Terms that start with R and view definitions. Read on for military definitions that begin with R such as reachback, reportable incident, retrograde, rules of engagement, and more.

Military Dictionary A to Z


See also Official DOD Shortened Word Forms.


radiation dose — The total amount of ionizing radiation absorbed by material or tissues.

radiation dose rate — Measurement of radiation dose per unit of time.

radiation exposure status — Criteria to assist the commander in measuring unit exposure to radiation based on total past cumulative dose, normally expressed in centigray. Also called RES.

radio frequency countermeasures — Any device or technique employing radio frequency materials or technology that is intended to impair the effectiveness of enemy activity, particularly with respect to precision guided weapons and sensor systems. Also called RF CM.

radiological dispersal device — An improvised assembly or process, other than a nuclear explosive device, designed to disseminate radioactive material to cause destruction, damage, or injury. Also called RDD.

radiological exposure device A radioactive source placed to cause injury or death. Also called RED.

radiological hazard — Ionizing radiation that can cause damage, injury, or destruction from either external irradiation or due to radiation from radioactive materials within the body.

raid — An operation to temporarily seize an area to secure information, confuse an enemy, capture personnel or equipment, or to destroy a capability culminating with a planned withdrawal.

railhead — A point on a railway where loads are transferred between trains and other means of transport.

Rangers — Rapidly deployable airborne light infantry organized and trained to conduct highly complex joint direct action operations in coordination with or in support of other special operations units of all Services.

rapid global mobility — The timely movement, positioning, and sustainment of military forces and capabilities across the range of military  operations.  See also  mobility.

rationalization — Any action that increases the effectiveness of allied forces through more efficient or effective use of defense resources committed to the alliance.

reachback — The process of obtaining products, services, and applications, or forces, or equipment, or material from organizations that are not forward deployed.

readiness — The ability of military forces to fight and meet the demands of assigned missions. See also national military strategy.

Ready Reserve The Selected Reserve and Individual Ready Reserve liable for active duty as prescribed by law (Title 10, United States Code, Sections 10142, 12301, and 12302). See also active duty; Individual Ready Reserve; Selected Reserve.

Realistic Military Training — Department of Defense training conducted off federal property utilizing  private  or  non-federal  public  property  and  infrastructure.

real property — Lands, buildings, structures, utilities systems, improvements, and appurtenances, thereto that includes equipment attached to and made part of buildings and structures, but not movable equipment.

reattack recommendation An assessment, derived from the results of battle damage assessment and munitions effectiveness assessment, providing the commander systematic advice on reattack of a target. Also called RR. See also assessment; battle damage assessment; munitions effectiveness assessment; target.

receiving ship — The ship in a replenishment unit that receives the rig(s).

reception — 1. All ground arrangements connected with the delivery and disposition of air or sea drops. 2. Arrangements to welcome and provide secure quarters or transportation for defectors, escapees, evaders, or incoming agents. 3. The process of receiving, off- loading, marshalling, accounting for, and transporting of personnel, equipment, and materiel from the strategic and/or intratheater deployment phase to a sea, air, or surface transportation point of debarkation to the marshalling area.

recognition — 1. The determination by any means of the individuality of persons, or of objects such as aircraft, ships, or tanks, or of phenomena such as communications- electronics patterns. 2. In ground combat operations, the determination that an object is similar within a category of something already known.

recognition signal — Any prearranged signal by which individuals or units may identify each other.

reconnaissance — A mission undertaken to obtain, by visual observation or other detection methods, information about the activities and resources of an enemy or adversary, or to secure data concerning the meteorological, hydrographic, or geographic characteristics of a particular area.

reconstitution — 1. Actions taken to rapidly restore functionality to an acceptable level for a particular mission, operation, or contingency after severe degradation. 2. Those actions, including regeneration and reorganization, commanders plan and implement to restore units to a desired level of combat effectiveness commensurate with mission requirements and available resources. 3. In maritime pre-positioning force operations, the methodical approach to restore the maritime pre-positioned equipment and supplies aboard the maritime pre-positioning ships squadron to full mission-capable status.

recovery — 1. In air (aviation) operations, that phase of a mission that involves the return of an aircraft to a land base or platform afloat. 2. The retrieval of a mine from the location where emplaced. 3. In personnel recovery, actions taken to physically gain custody of isolated personnel and return them to  friendly  control. 4. Actions taken to extricate damaged or disabled equipment for return to friendly control or repair at another location. See also evader; evasion.

recovery and reconstitution — 1. Those actions taken by one nation prior to, during, and following an attack by an enemy nation to minimize the effects of the attack, rehabilitate the national economy, provide for the welfare of the populace, and maximize the combat potential of remaining forces and supporting activities. 2. Those actions taken by a military force during or after operational employment to restore its combat capability to full operational readiness. See also recovery. 

recovery mechanism — An indigenous or surrogate infrastructure that is specifically developed, trained, and directed by United States forces to contact, authenticate, support, move, and exfiltrate designated isolated personnel from uncertain or hostile areas back to friendly control. Also called RM.

recovery operations — Operations conducted to search for, locate, identify, recover, and return isolated personnel, human remains, sensitive equipment, or items critical to national security.

recovery site — In personnel recovery, an area from which isolated personnel can be recovered. See also escapee; evader; evasion.

recovery team — In personnel recovery, designated United States or United States-directed forces, that are specifically trained to operate in conjunction with indigenous or surrogate forces, and are tasked to contact, authenticate, support, move, and exfiltrate isolated personnel. Also called RT.

recovery vehicle — In personnel recovery, the vehicle on which isolated personnel are boarded and transported from the recovery site.

redeployment — The transfer or rotation of forces and materiel to support another commander’s operational requirements, or to return personnel, equipment, and material to the home and/or demobilization stations for reintegration and/or out-processing. See also deployment.

red team — An organizational element comprised of trained and educated members that provide an independent capability to fully explore alternatives in plans and operations in the context of the operational environment and from the perspective of adversaries and others.

reduced operating status — Military Sealift Command ships withdrawn from full operating status because of decreased operational requirements. Also called ROS. See also Military Sealift Command.

reduction — The creation of lanes through a minefield or obstacle to allow passage of the attacking ground force.

refraction — The process by which the direction of a wave is changed when moving into shallow water at an angle to the bathymetric contours.

refugee — A person who, owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group, or political opinion, is outside the country of his or her nationality and is unable or, owing to such fear, is unwilling to avail himself or herself of the protection of that country. See also dislocated civilian; displaced person; evacuee; stateless person.

regimental landing team — A task organization for landing composed of an infantry regiment reinforced by those elements that are required for initiation of its combat function ashore. Also called RLT.

regional air defense commander — Commander, subordinate to the area air defense commander, who is responsible for air and missile defenses in the assigned region and exercises authorities as delegated by the area air defense commander. Also called RADC.

regional response coordination center — A standing facility that is activated to coordinate regional response efforts until a joint field office is established and/or the principal federal official or coordinating officer can assume their National Response Framework coordination responsibilities. Also called RRCC.

regional security officer — A security officer responsible to the chief of mission (ambassador), for security functions of all United States embassies and consulates in a given country or group of adjacent countries. Also called RSO.

rehabilitative care — Therapy that provides evaluations and treatment programs using exercises, massage, or electrical therapeutic treatment to restore, reinforce, or enhance motor performance and restores patients to functional health allowing for their return to duty or discharge from the Service. Also called restorative care. See also patient movement policy; theater.

rehearsal phase In amphibious operations, the period after embarkation and prior to the action phase during which the prospective operation is practiced. See also amphibious operation.

reinforcing obstacles — Those obstacles specifically constructed, emplaced, or detonated through military effort and designed to strengthen existing terrain to disrupt, fix, turn, or block enemy movement. See also obstacle. 

reintegrate — In personnel recovery, the task of providing medical care and psychological decompression to allow the conduct of appropriate debriefings to ultimately return recovered personnel back to duty and their family.

release altitude — Altitude of an aircraft above the ground at the time of ordnance release.

relief in place — An operation in which, by direction of higher authority, all or part of a unit is replaced in an area by the incoming unit and the responsibilities of the replaced elements for the mission and the assigned zone of operations are transferred to the incoming unit.

religious advisement — The practice of informing the commander on the impact of religion on operations, to include, but not limited to, worship, rituals, customs, and practices of United States military personnel, international forces, and the indigenous population, as well as the impact of military operations on the religious and humanitarian dynamics in the operational area.

religious affairs — The combination  of  religious  support  and  religious  advisement.

religious discrimination — The unlawful limits on religious expression; punishment for religious beliefs or lack of belief; or the compulsion to express opinions or beliefs contrary to religious beliefs of established religions

religious support — Chaplain-facilitated free exercise of religion through worship, religious and pastoral counseling services, ceremonial honors for the fallen, crisis intervention, and advice to the commander on ethical and moral issues and morale. Also called RS.

religious support team — A team comprising at least one chaplain and one enlisted religious affairs person. Also called RST.

remain-behind equipment Unit equipment left by deploying forces at their bases when they deploy.

render safe procedures — The portion of the explosive ordnance disposal procedures involving the application of special explosive ordnance disposal methods and tools to provide for the interruption of functions or separation of essential components of unexploded explosive ordnance to prevent an unacceptable detonation.

rendezvous area — In an amphibious operation, the area in which the landing craft and amphibious vehicles rendezvous to form waves after being loaded and prior to movement to the line of departure.

repairable item — An item that can be reconditioned or economically repaired for reuse when it becomes unserviceable.

repair cycle — The stages through which a repairable item passes from the time of its removal or replacement until it is reinstalled or placed in stock in a serviceable condition.

repatriation — 1. The procedure whereby American citizens and their families are officially processed back into the United States subsequent to an evacuation. See also evacuation. 2. The release and return of enemy prisoners of war to their own country in accordance with the 1949 Geneva Convention Relative to the Treatment of Prisoners of War.

replacement in kind — The provision of material and services for a logistic exchange of materials and services of equal value between the governments of eligible countries. Also called RIK.

reportable incident — Any suspected or alleged violation of Department of Defense policy or of other related orders, policies, procedures or applicable law, for which there is credible information.

request for assistance — A request based on mission requirements and expressed in terms of desired outcome formally asking the Department of Defense to provide assistance within the United States or United States territories to a local, state, tribal, or other federal agency. Also called RFA.

request for information — 1. Any specific time-sensitive ad hoc requirement for intelligence information or products to support an ongoing crisis or operation not necessarily related to standing requirements or scheduled intelligence production. 2. A term used by the National Security Agency/Central Security Service to state ad hoc signals intelligence requirements. Also called RFI. See also intelligence. 

requirements determination — All activities necessary to develop, consolidate, coordinate, validate, approve, and prioritize joint force contract support requirements.

requirements development — The process of defining actual contract support requirements and capturing these requirements in acquisition ready contract support requirements packages.

requiring activity — A military or other designated supported organization that identifies and receives contracted support during military operations. See also supported unit.

rescue combat air patrol — An aircraft patrol provided over that portion of an objective area in which recovery operations are being conducted for the purpose of intercepting and destroying hostile aircraft. Also called RESCAP. See also combat air patrol.

rescue coordination center — A unit, recognized by International Civil Aviation Organization, International Maritime Organization, or other cognizant international body, responsible for promoting efficient organization of search and rescue services and coordinating the conduct of search and rescue operations within a search and rescue region. Also called RCC.

reserve — 1. Portion of a body of troops that is kept to the rear or withheld from action at the beginning of an engagement to be available for a decisive movement. 2. Members of the uniformed Services who are not in active service but who are subject to call to active duty. 3. Portion of an appropriation or contract authorization held or set aside for future operations or contingencies and, in respect to which, administrative authorization to incur commitments or obligations has been withheld.

Reserve Component — The Armed Forces of the United States Reserve Component consists of the Army National Guard of the United States, the Army Reserve, the Navy Reserve, the Marine Corps Reserve, the Air National Guard of the United States, the Air Force Reserve, and the Coast Guard Reserve. Also called RC. See also component; reserve.

reserved obstacles — Those demolition obstacles that are deemed critical to the plan for which the authority to detonate is reserved by the designating commander. See also obstacle.

reset — A set of actions to restore equipment to a desired level of combat capability commensurate with a unit’s future mission.

resettled person — A refugee or an internally displaced person wishing to return somewhere other than his or her previous home or land within the country or area of original displacement.

residual forces — Undeployed United States forces that have an immediate combat potential for continued military operations, and that have been deliberately withheld from utilization.

residual radiation — Nuclear radiation caused by fallout, artificial dispersion of radioactive material, or irradiation that results from a nuclear explosion and persists longer than one minute after burst. See also contamination; prompt radiation.

resistance movement — An organized effort by some portion of the civil population of a country to resist the legally established government or an occupying power and to disrupt civil order and stability.

resource management — A financial management function that provides advice and guidance to the commander to develop command resource requirements. Also called RM. See also financial management.

resources — The forces, materiel, and other assets or capabilities apportioned or allocated to the commander of a unified or specified command.

rest and recuperation — The withdrawal of individuals from combat or duty in a combat area for short periods of rest and recuperation. Also called R&R.

restraint — In the context of planning, a requirement placed on the command by a higher command that prohibits an action, thus restricting freedom of action. See also constraint; limitation.

restricted area — 1. An area (land, sea, or air) in which there are special restrictive measures employed to prevent or minimize interference between friendly forces. 2. An area under military jurisdiction in which special security measures are employed to prevent unauthorized entry. See also restricted areas (air).

restricted areas (air) — Designated areas established by appropriate authority over which flight of aircraft is restricted. See also restricted area.

restricted items list — A document listing those logistic goods and services for which nations must coordinate any contracting activity with a commander’s centralized contracting organization.

restricted operations zone — Airspace reserved for specific activities in which the operations of one or more airspace users is restricted. Also called ROZ.

restricted reporting — Reporting option that allows sexual assault victims to confidentially disclose the assault to specified individuals (e.g., sexual assault response coordinator, sexual assault prevention and response victim advocate, or healthcare personnel) and receive medical treatment and counseling without triggering an official investigation.

restricted target — A valid target that has specific restrictions placed on the actions authorized against it due to operational considerations. See also target.

restricted target list — A list of restricted targets nominated by elements of the joint force and approved by the joint force commander or directed by higher authorities. Also called RTL. See also restricted target; target.

restrictive fire area — An area in which specific restrictions are imposed and into which fires that exceed those restrictions will not be delivered without coordination with the establishing headquarters. Also called RFA. See also fires.

restrictive fire line — A line established between converging friendly surface forces that prohibits  fires or their effects across that line. Also called RFL.  See also fires.

resupply — The act of replenishing stocks in order to maintain required levels of supply.

resuscitative care — Advanced emergency medical treatment required to prevent immediate loss of life or limb and to attain stabilization to ensure the patient could tolerate evacuation.

retained personnel — Detainees who fall into one of the following categories: a. Designated enemy medical personnel and medical staff administrators who are exclusively engaged in either the search for, collection, transport, or treatment of the wounded or sick, or the prevention of disease; b. Staff of National Red Cross and Red Crescent Societies and that of other volunteer aid societies, duly recognized and authorized by their governments to assist medical service personnel of their own armed forces, provided they are exclusively engaged in the search for, or the collection, transport or treatment of wounded or sick, or in the prevention of disease, and provided that the staff of such societies are subject to military laws and regulations; c. Chaplains attached to enemy armed forces. Also called RP. See also personnel.

Retired Reserve — All reserve members who receive retirement pay on the basis of their active duty and/or reserve service; those members who are otherwise eligible for retirement pay but have not reached age 60 and who have not elected discharge and are not voluntary members of the Ready Reserve or Standby Reserve. See also active duty; Ready Reserve; Standby Reserve.

retrograde — The process for the movement of non-unit equipment and materiel from a forward location to a reset (replenishment, repair, or recapitalization) program or to another directed area of operations to replenish unit stocks, or to satisfy stock requirements.

returnee — A displaced person who has returned voluntarily to his or her former place of residence.

return to base — An order to proceed to the point indicated by the displayed information or by verbal communication. Also called RTB.

revolving fund account — An account authorized by specific provisions of law to finance a continuing cycle of business-type operations, and which are authorized to incur obligations and expenditures that generate receipts.

riot control agent — Any chemical, not listed in a schedule of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction that can produce rapidly in humans sensory irritation or disabling physical effects that disappear within a short time following termination of exposure. Also called RCA. See also chemical warfare.

rising mine — In naval mine warfare, a mine having positive buoyancy, which is released from a sinker by a ship influence or by a timing device.

risk assessment — The identification and assessment of hazards (first two steps of risk management process). Also called RA.

risk management — The process to identify, assess, and control risks and make decisions that balance risk cost with mission benefits. Also called RM.

riverine operations — Operations conducted by forces organized to cope with the unique characteristics of a riverine area and/or to achieve or maintain control of the riverine area.

role specialist nation — A nation that has agreed to assume responsibility for providing a particular class of supply or service for all or part of the multinational force. Also called RSN. See also lead nation; multinational force.

roles of medical care — The characterization of health support for the distribution of medical resources and capabilities. a. Role 1. Provides medical treatment, initial trauma care, and forward resuscitation, not including surgical care. Also known as unit-level medical care. b. Role 2. Provides medical treatment, advanced trauma management, emergency surgery, and resuscitative care. c. Role 3. Provides emergency and specialty surgery, intensive care, medical specialty care, and extended holding capacity and capability augmented by robust ancillary support. d. Role 4. Provides the full range of preventive, acute, restorative, curative, rehabilitative, and convalescent care found in United States base hospitals and robust overseas facilities.

roll-on/roll-off discharge facility — A platform made up of causeway sections that provide a means of embarking and disembarking vehicles from a roll-on and roll-off ship at sea to lighterage. Also called RRDF. See also facility; lighterage.

rough terrain container handler — A piece of materials handling equipment used to pick up and move containers. Also called RTCH.

rules of engagement — Directives issued by competent military authority that delineate the circumstances and limitations under which United States forces will initiate and/or continue combat engagement with other forces encountered. Also called ROE. See also law of war.

ruse — In military deception, an action designed to deceive the adversary, usually involving the deliberate exposure of false information to the adversary’s intelligence collection system.

Military Dictionary A to Z


See also Official DOD Shortened Word Forms.

Source: Official DOD Dictionary of Military and Associated Terms.