| Acronym | Definition |
|---|
| PISI➣Pine Siskin (bird species) |
| PISI➣Port-Injection Spark-Ignition (engine) |
| PISI➣Palpap Ichinichi Software International (India) |
| PISI➣Palmar Intercalated Segment Instability (hand ligaments) |
| PISI➣Prudentialife Information Systems, Inc. (Makati, Philippines) |
| PISI➣Prognostic Index of Surgical Infections (gastroenterology) |