| Acronym | Definition |
|---|
| AT | Advanced Technology (IBM PC AT personal computer) |
| AT | Automatic Transmission |
| AT | Appalachian Trail |
| AT | Attention |
| AT | Austria (top-level domain name) |
| AT | Automatic |
| AT | All That (Nickelodeon TV show) |
| AT | Atmosphere |
| AT | Attachment |
| AT | Atomic |
| AT | Air Traffic |
| AT | In Transit (Austrian cancel mark; philately) |
| AT | Assistive Technology |
| AT | All Terrain |
| AT | Air Transport |
| AT | Anti-Terrorism |
| AT | Air Temperature |
| AT | Ambient Temperature |
| AT | Airtight |
| AT | Audit Trail |
| AT | Atlantic Time |
| AT | Angiotensin |
| AT | Automotive Technology |
| AT | Applicant Tracking (human resources) |
| AT | Access Time |
| AT | AppleTalk (Apple local area network technology) |
| AT | Appropriate Technology |
| AT | Anti-Terrorist |
| AT | Alkaline Trio (band) |
| AT | Attenuator |
| AT | Available Time (Itu-T) |
| AT | Anti-Tank |
| AT | Applied Technology |
| AT | Antarctic Treaty |
| AT | Ashmore and Cartier Islands |
| AT | Access Type |
| AT | Anti-Trojan (computer security) |
| AT | Annual Training |
| AT | Argentine Tango |
| AT | Acceptance Testing |
| AT | Army Training |
| AT | Acceptance Test |
| AT | Anandtech.com (website) |
| AT | Aerotech (model rocket corporation) |
| AT | Antithrombin |
| AT | Attribute Table |
| AT | Ataxia-Telangiectasia |
| AT | Alta Tensión (Spanish: High Voltage) |
| AT | Application Technologies |
| AT | Antiguo Testamento (Spanish: from the bible) |
| AT | Advanced Treatment (environment) |
| AT | Atomic Time |
| AT | Alimentary Tract |
| AT | Annual Tour |
| AT | Alternative Tentacles (record label) |
| AT | Astatine |
| AT | Altes Testament (German: Old Testament) |
| AT | Access Transport (Sprint) |
| AT | Academically Talented |
| AT | Animal Transport |
| AT | Atraumatic (physical exam) |
| AT | Acquisition Team |
| AT | Anaerobic Threshold |
| AT | Atrial Tachycardia |
| AT | Arranged Team (gaming) |
| AT | Averaging Time |
| AT | Allowance Type |
| AT | Application Tape |
| AT | Alexander Technik |
| AT | Army Transformation (US Army) |
| AT | Asynchronous Transmission |
| AT | Armored Trooper (anime) |
| AT | Anti-Tampering |
| AT | Alert Time |
| AT | Absolute Terror |
| AT | Awaiting Transfer |
| AT | Azores Time (GMT-0200) |
| AT | Auto Transformer |
| AT | Atmospheric Transmission |
| AT | Alpha Track (detection) |
| AT | Astronomy Tower (fanfiction) |
| AT | Aviation Electronics Technician (USN Rating) |
| AT | Adenine-Thymine (DNA base pairing) |
| AT | Asti, Piemonte (Italian province) |
| AT | Awaiting Transportation |
| AT | Acceptance Trials |
| AT | Aviation Electronics Technician (Navy Rate) |
| AT | Access Tandem |
| AT | Anterior Tibialis (dorsiflexor) |
| AT | Active Terminator (SCSI terminator) |
| AT | Royal Air Maroc, Morocco (IATA airline code) |
| AT | Asynchronous Terminal |
| AT | Avian Tuberculosis |
| AT | Analytical Task |
| AT | Anchorage Times (Anchorage, AK newspaper) |
| AT | America's Talking (NBC show; 1994 and 1995) |
| AT | Angst Technology (web comic strip) |
| AT | Average Torque |
| AT | Automatic Ticketing |
| AT | Administrative Trainee |
| AT | Assay Ton |
| AT | Aero Triangulation |
| AT | Ampere-Turn (measure of magneto motive force) |
| AT | Acceptance Trial |
| AT | Askarel Transformer |
| AT | Ampacity Tables |
| AT | After Tendulkar (India, sports) |
| AT | Action Toolbelt (band) |
| AT | Answering Tone |
| AT | Alaska Telecommunications |
| AT | Army Telegraph (philatelic overprint, South Africa) |
| AT | Abnormal Transient |
| AT | Aliveness Test |
| AT | Acceptance Tag |
| AT | Atomic Terrorism |
| AT | Antenna Trainer |
| AT | Astrometry Team |
| AT | Applanation Tension (pressure in the eye) |
| AT | Accelerator Operations and Technology |
| AT | Arabesque Travel |
| AT | Adaptive Two-Step (IEEE) |
| AT | Autonomous Transporter |
| At | total attainable search area (US DoD) |
| AT | Antithromin Activity |
| AT | Architectural Technologist/Techinician (professional accreditation) |