| Abbreviation | Definition |
|---|---|
| ARC | Aramaic |
| ARC | Arctic |
| ARM | Armenian |
| ARN | Araucanian |
| ARP | Arapaho |
| ART | Artificial (Other) |
| ARV | Cushitic: East: Western Omo-Tana: ARBORE |
| ARW | Arawak |
| ASL | American Sign Language |
| ASM | Assamese |
| ASP | As Soon As Possible |
| ATH | Athabascan Languages |
| ATZ | ARTA: A language of the Philippines |
| AVA | Avaric |
| AVE | Avestan |
| AWA | Awadhi |
| AYM | Aymara |
| AZE | Azerbaijani |
| BAD | Banda |
| BAI | Bamileke Languages |