| Acronym | Definition |
|---|
| TRIS | Tris(Hydroxymethyl)aminomethane |
| TRIS | Tri-State |
| TRIS | Transportation Research Information Service (US Dept. of Transportation) |
| TRIS | Traffic and Road Information System (Canada) |
| TRIS | Pilatus Britten-Norman BN-2A Mk III Trislander (aircraft; UK) |
| TRIS | Toxic Chemical Release Inventory System (US EPA; also seen as TCRIS) |
| TRIS | Trapped Ions in Space (experiment) |
| TRIS | Telephone Routing Interactive System |
| TRIS | Training Records Information System |
| TRIS | Transportation Rate Information System |
| TRIS | Training Requirements & Information System |