| ABS | Anti-lock Braking System |
| AC | Air Conditioner |
| ACL | Anterior Cruciate Ligament |
| ACT | American College Testing (as in ACT Test) |
| AD | Anno Domini (Latin for "In The Year of The/Our Lord") (Year, e.g. 2,500 AD) |
| ADD | Attention Deficit Disorder |
| ADHD | Attention Deficit Hyperactivity Disorder |
| AIDS | Acquired Immune Deficiency (also Acquired ImmunoDeficiency) Syndrome |
| AKA | Also Known As |
| AM | Ante Meridiem (Latin for "Before Noon/Midday") |
| APB | All-Points Bulletin |
| APC | Armored Personnel Carrier |
| APO | Army (or Air Force) Post Office |
| APR | Annual Percentage Rate |
| APY | Annual Percentage Yield |
| ARM | Adjustable-Rate Mortgage |
| ASAP | As Soon As Possible |
| ATF | Bureau of Alcohol, Tobacco, Firearms and Explosives |
| ATM | Automated Teller Machine |
| ATV | All-Terrain Vehicle |
| AWACS | Airborne Warning And Control System |
| AWOL | Absent WithOut (also Absent Without Official) Leave |
| BC | Before Christ (Year, e.g. 10,000 BC) |
| BMI | Body Mass Index |
| CC | Carbon (or Courtesy) Copy (Letter, E-Mail) • Closed Captioning • Cubic Centimeter (cm3) |
| CPR | CardioPulmonary Resuscitation |
| DJ | Disc (also Disk) Jockey |
| DNA | DeoxyriboNucleic Acid |
| ESP | ExtraSensory Perception |
| ETA | Estimated Time of Arrival |
| FAQ | Frequently Asked Questions |
| FYI | For Your Information |
| GI | Government Issue |
| GM | General Manager |
| HIV | Human Immunodeficiency Virus |
| HR | Human Resources |
| i.e. | Id Est (Latin for "That is" or "In Other Words") |
| IQ | Intelligence Quotient |
| KKK | Ku Klux Klan |
| KO | KnockOut |
| LASIK | Laser-Assisted in SItu Keratomileusis |
| LOL | Laugh(ing) Out Loud |
| MO | Modus Operandi (Latin for "Mode of Operating") |
| MRI | Magnetic Resonance Imaging |
| NASA | National Aeronautics and Space Administration |
| NATO | North Atlantic Treaty Organization |
| OPEC | Organization of the Petroleum Exporting Countries |
| OR | Operating Room |
| PR | Public Relations • Problem Report |
| PVC | PolyVinyl Chloride |
| Q&A | Questions and Answers |
| QC | Quality Control |
| R&D | Research and Development |
| REM | Rapid Eye Movement (Sleep Stage) |
| SCUBA | Self-Contained Underwater Breathing Apparatus |
| STD | Sexually Transmitted Disease |
| TB | TuBerculosis |
| TOC | Table Of Contents |
| UPC | Universal Product Code |
| UV | UltraViolet |
| 2G | Second Generation |
| 3D | Three-Dimensional |
| 3G | Third Generation |
| 4WD | Four-Wheel Drive |