| Abbreviation | Definition |
|---|---|
| AIN | anterior interpositus nucleusanatomy |
| AIN | anterior interpositus nucleus–anatomy |
| AIN | assistant in nursing |
| AIN | autoimmune neutropenia |
| AIOPI | Association of Information Officers in the Pharmaceutical Industry |
| AIRA | American International Reiki Association |
| AIRS | Access Issues Resolution Service |
| AIS | adenocarcinoma in situ |
| AIS | alcohol insoluble solids Food industry |
| AIS | anal carcinoma in situ |
| AIS | androgen-insensitivity syndrome |
| AIS | anterior interosseous nerve syndrome |
| AIS | anti-insulin serum???no longer used |
| AIS | anti-insulin serumno longer used |
| AIS | anti-insulin serum–no longer used |
| AIS | attitude indicating system |
| AIT | adoptive immunotherapy |
| AIT | after-image transfer |
| AIT | anterior inferotemporal |
| AIT | antibody-incompatible transplantation |