| Acronym | Definition | 
|---|
| MASI➣Melasma Area and Severity Index (dermatology) | 
| MASI➣Manhattan Sites (US National Park Service) | 
| MASI➣Metropolitan Andrey Sheptytsky Institute (Saint Paul University; Ottawa, Canada) | 
| MASI➣Major Acquisition Systems Infrastructure (US Coast Guard) | 
| MASI➣Mach Airspeed Indicator | 
| MASI➣Multithreaded Architecture for Software I/O | 
| MASI➣ManTech Advanced Systems International, Inc. (Glen Burnie, MD) | 
| MASI➣Member of the Architectural and Surveying Institute |