| Acronym | Definition |
|---|
| PIRA➣Provisional Irish Republican Army |
| PIRA➣Physics Instructional Resource Association |
| PIRA➣Petroleum Industry Research Associates (PIRA Energy Group) |
| PIRA➣Precision Impact Range Area |
| PIRA➣PADI International Resort Association |
| PIRA➣Paper Industry Research Association |
| PIRA➣Printing Industries Research Association |
| PIRA➣Personnel and Industrial Relations Association (est. 1945; Los Angeles, CA) |
| PIRA➣Parachute Infantry Regiment Association (UK) |
| PIRA➣Philippine Insurance Rating Association |
| PIRA➣Paper, Printing and Packaging Industries Research |
| PIRA➣Pre-Inactivation Restricted Availability (US Navy) |
| PIRA➣Plastics Industry Research Association (UK) |