| Acronym | Definition |
|---|
| RA | Rental Agreement |
| RA | Rain (aviation meteorology) |
| RA | Rheumatoid Arthritis |
| RA | Rapport |
| RA | Ravenna (Emilia Romagna, Italy) |
| RA | Right Ascension (astronomy) |
| RA | Remote Access |
| RA | Rechtsanwalt (German: attorney) |
| RA | Risk Assessment |
| RA | Radon |
| RA | Return Authorization |
| RA | Royal Academy |
| RA | Rise Against (band) |
| RA | Radium |
| RA | Red Alert (computer game) |
| RA | Red Alert |
| RA | Random Access |
| RA | Remedial Action |
| RA | Resident Advisor |
| RA | Research Associate |
| RA | Return Address (register) |
| RA | Registration Authority |
| RA | Research Article |
| RA | Risk Analysis |
| RA | Regulatory Affairs |
| RA | Resident Assistant |
| RA | Rehabilitation Act of 1973 |
| RA | Radiocommunication Assembly |
| RA | Resource Allocation |
| RA | Radio Australia |
| RA | Republic of Armenia |
| RA | República Argentina |
| RA | Rural Area (terrain type) |
| RA | Router Advertisement (Message) |
| RA | Radiocommunications Agency (within DTI) |
| RA | Regulatory Authority |
| RA | Republic Act (Philippines) |
| RA | Room Air |
| RA | Rainforest Alliance |
| RA | Right Atrium (heart chamber) |
| RA | Regional Administrator |
| RA | Radio Access |
| RA | Red Army (counterstrike gaming clan) |
| RA | Red Army (WWII Soviet army) |
| RA | Reliability Analysis |
| RA | Rear Admiral |
| RA | Regular Army |
| RA | Royal Artillery |
| RA | Rapid Access |
| RA | Remittance Advice |
| RA | Reserve Affairs |
| RA | Regional Anesthesia |
| RA | Rankine |
| RA | Regional Association |
| RA | Ready Access |
| RA | Restricted Areas |
| RA | Residents' Association |
| RA | Ray Allen (basketball player) |
| RA | Reasonable Alternative |
| RA | Royal Nepal Airlines (IATA airline code) |
| RA | Ram-Air (General Motors) |
| RA | Requirements Analysis |
| RA | Ramblers Association (UK) |
| RA | Rebel Alliance (Star Wars) |
| RA | Radar Altimeter |
| RA | Remote Agent |
| RA | Rocket Arena (gaming site) |
| RA | Remote Assistance |
| RA | Removal Action |
| RA | Royal Ambassadors |
| RA | Irish Republican Army |
| RA | RealAudio File (proprietary streaming audio compression format, Real Networks) |
| RA | Roman Army |
| RA | Rationalist Association (UK) |
| RA | Registered Architect |
| RA | Random Allocation |
| RA | Rate-Adaptive |
| RA | Resident Agent |
| RA | Resolution Advisory (air traffic warning) |
| RA | Roald Amundsen (1st explorer to reach the South Pole) |
| RA | Royal Arch (Masons) |
| RA | Radio Authority (UK) |
| RA | Reconnaissance Aircraft |
| RA | Responsible Authorities |
| RA | Research Announcement |
| Ra | Rate of Appearance |
| RA | Return Air (HVAC) |
| RA | Rabbinical Assembly |
| RA | Radiological Assessment |
| RA | Regulatory Analysis (environment) |
| RA | Revenue Account (UK) |
| RA | Rate Adaptation |
| RA | Realtor Associate |
| RA | Radio Altimeter |
| RA | Routing Arbiter |
| RA | Realm Ability (Dark Age of Camelot on-line game) |
| RA | Red Armor (gaming) |
| RA | Rear Area |
| RA | Registration Agent (SIF) |
| RA | Remington Arms (ammunition headstamp) |
| RA | Repair Authorization |
| RA | Regia Aeronautica (Italian Royal Air Force) |
| RA | Recovery Assistance (Program; Ohio) |
| RA | Red Armour (Quake) |
| RA | Roughness Average (Surface texture of materials) |
| RA | Relational Aggression (psychology) |
| RA | Radiographic Absorptiometry (bone density calculation using a hand X-ray and a small metal wedge) |
| RA | Relay Access |
| RA | Reduction in Area |
| RA | Resource Advisor |
| RA | Rate Area (NANPA) |
| RA | Radiallahu Anhu (companions of Prophet Mohammed) |
| RA | revenue analysis |
| RA | Regular Appointment |
| RA | Resource Analyst |
| RA | Rubberized Asphalt |
| RA | Remote Adapter |
| RA | Roaming Agreement |
| RA | Recoveries Anonymous (Twelve Step Fellowship) |
| RA | Recorded Achievement ( Australian academics) |
| RA | Regulatory Alternative |
| RA | Restricted Article |
| RA | Requesting Activity (CEFMS) |
| RA | Reduction Area |
| RA | Reattack |
| RA | Rescue Aid (emergency communications) |
| RA | Radiocommunication Act |
| RA | Resident Auditor |
| RA | Runs Allowed per 9 Innings (baseball; like ERA, but with unearned runs also) |
| RA | Ready Alert |
| RA | Ration Allowance |
| RA | Retribution Aura (gaming, World of Warcraft) |
| RA | Resident Administrator |
| RA | Ripple Adder |
| RA | Postal Tax Stamp (Scott Catalogue prefix; philately) |
| RA | Reimbursement Authorization |
| RA | Red Armageddon (gaming clan) |
| RA | Repeat and Accumulate (type codes) |
| RA | Robot Aircraft |
| RA | Ready Analog |
| RA | Record Auditing |
| RA | Restricted Artistic (movie rating) |
| RA | Run Aggressive (Front Page Sports Football '95 et al) |
| RA | Roundhead Association (historical reenactment group) |
| RA | Router Arbiter |
| RA | reduced ameloblasts |
| RA | Raufoss Ammunition (Norwegian ammunition headstamp) |
| RA | Radiology Assembly of Medical Group Management Association |
| RA | Research Assistant/ship |
| RA | Reinforced Alert |
| RA | Recruit Alliance |
| RA | Earned Run Average Plus (arcane baseball statistic; used to measure pitching dominance versus the league) |
| RA | Registraramerica (domain name registrar) |
| RA | Review/Requiring Activity |
| RA | Resynchronize Acknowledgement (ITU-T) |
| RA | Route Analysis CSCI |
| RA | Routing Area Identifier Within Routing Domain (TMN) |
| RA | Religious of the Assumption (France) (religious order) |