| Acronym | Definition |
|---|
| AIN | Advanced Intelligent Network |
| AIN | Acute Interstitial Nephritis |
| AIN | American Institute of Nutrition |
| AIN | Anal Intraepithelial Neoplasia |
| AIN | Animal Identification Number (US Department of Agriculture) |
| AIN | Auto-Insert Notification (CD-R) |
| AIN | Andean Information Network (Bolivia) |
| AIN | Army Installation |
| AIN | American Indian Native |
| AIN | Assistant In Nursing |
| AIN | Anterior Interosseous Nerve (median nerve branch) |
| AIN | American Independent Network (Television) |
| AIN | Wainwright, AK, USA (Airport Code) |
| AIN | Approved Item Name |
| AIN | Army Interoperability Network |
| AIN | Associazione Italiana Neurodisabili (Italian Neurodisabity Association) |
| AIN | Asynchronous Interface Module (Cisco) |
| AIN | Artists Independent Network |
| AIN | Ammunition Information Notice |
| AIN | Aerospace Innovation Network |
| AIN | Audentior Independent Nation |
| AIN | Assembly Identification Number |
| AIN | Army Information Network |
| AIN | Alabama Information Network |
| AIN | Agent Identification Number |
| AIN | Ayuda de la Iglesia de Noruega (Aid for the Church of Norway, Guatemala) |
| AIN | Autonomous Individuals Network (Sacramento, CA) |
| AIN | Association des Infirmiers en Neurologie |
| AIN | Associazione Infanzia Nefropatica |
| AIN | Admission Index Number (student evaluation) |
| AIN | Apikan Indigenous Network |
| AIN | Advocacy Initiative Network (Maine) |