| Acronym | Definition |
|---|
| MCLL➣Most Comfortable Listening Level (audiometry) |
| MCLL➣Modern and Classical Languages and Literatures (academic department; various universities) |
| MCLL➣Marine Corps Lessons Learned |
| MCLL➣Missile Compartment Lower Level (compartment of a US Navy nuclear submarine) |
| MCLL➣Meiklejohn Civil Liberties Library (Berkeley, CA) |