| Acronym | Definition |
|---|
| MCRR➣Medical Care Research and Review |
| MCRR➣Midwest Central Railroad (Mount Pleasant, IA) |
| MCRR➣Michigan Central Railroad |
| MCRR➣Machine Check Recording and Recovery |
| MCRR➣Marine Corps Recruiting Ribbon (US DoD) |
| MCRR➣Movement Control and Readiness Reporting |
| MCRR➣Main Cardiovascular-Respiratory Rhythm (neurophysiology) |