| Abbreviation | Definition |
|---|---|
| AD | Active Directory |
| AD | Abdominal Diaphragmatic Breathing |
| AD | Adenovirus |
| AD | Auris Dextra, Right Ear |
| AD | Admitting Diagnosis |
| AD | Adult Disease |
| AD | Alternating Days |
| AD | After Death |
| AD | Auditory Discrimination |
| AD | Alzheimer's Disease |
| AD | Aortic Diameter |
| AD | Acute Disorder |
| AD | Arterial Device |
| AD | Attention Deficit |
| AD | Amoebic Dysentery |
| AD | Anatomic Design |
| AD | Assistant Deputy |
| AD | Always Dependable |
| AD | Assistant Director |
| AD | Art Director |
| AD | Always Demanding |
| AD | Acronym Director |
| AD | Audio Disks |
| AD | Admission and Discharge |
| AD | As Directed |
| AD | Analog Disc |
| AD | Accidental Death |
| AD | Almost Dead |
| AD | Application Development |
| AD | Applications Development |
| AD | Abductor Digiti Minimi |
| AD LIB | As desired |
| AD-CHF | Acutely Decompensated Congestive Heart Failure |
| ADA | Automated Degree Audit |
| ADA | Analog Digital Analog |
| Ada | Language after Augusta Ada Byron, computer pioneer |
| ADA | Anterior descending artery |
| ADA | Adenosine DeAminase |
| ADA | Apprentice Dark Angel |
| ADA | Aviation Data and Analysis System |
| ADA | Americans with Disabilities Act |
| ADA | Anti Deer Association |
| ADA | Alternatives To Domestic Aggression |
| ADA | Attorneys Dreams Answered |
| ADA | American Disabilities Act |
| ADA | Americans Dollars For Attorneys |
| ADA | Assistant District Attorney |
| ADA | Average Daily Attendance |
| ADA | American Dietetic Association |
| ADA | American Diabetes Association |