| Abbreviation | Definition |
|---|---|
| MSIP | Multinational Staged Improvement Program |
| MSNA | Multi-Sector Needs Assessment |
| MSO | Mission Security Officer |
| MSW | Municipality Solid Waste |
| MTS | Medium Term Strategy (of the UNEP) |
| MTSIP | Medium Term Strategic and Institutional Plan |
| MUN | Mdoel United Nations |
| MUN | Model United Nations |
| MUNA | Model United Nations Alfrink |
| MUNA | Model United Nations Assembly |
| MUNDA | Model United Nations Discussion Area |
| MUNFW | Model United Nations - Far West |
| MUN-FW | Model United Nations - Far West |
| MUNGA | Model United Nations General Assembly |
| MVI | Malaria Vaccine Initiative |
| NAA | Newly Accessible Area |
| NAFS | NATO Automated Financial System |
| NAIMUN | North American Invitational Model United Nations |
| NAIMUN | North American Invitational Model United Nations Conference |
| NAP | Neighborhood Action Plan |