| Maryland State Soccer Association |
Sports |
MSSA |
| Multiple Sclerosis South Africa |
Organization |
MSSA |
| Military Style Semi Automatic |
Military and Defence |
MSSA |
| Military Selective Service Act |
Misc |
MSSA |
| Mansoura Students Scientific Association |
University |
MSSA |
| Maryland State Sportsmen's Association |
Sports |
MSSA |
| Mess Specialist Seaman Apprentice |
Military |
MSSA |
| Montana Shooting Sports Association |
Sports |
MSSA |
| Minnesota Social Service Association |
Organization |
MSSA |
| Methicillin Sensitive Staphylococcus Aureus |
Physiology |
MSSA |
