| Abbreviation | Definition |
|---|---|
| MSLD | Mass Spectrometer Leak Detector |
| MST | Memotron Storage Tube |
| MST | Modular Spectroscopy Technology |
| MSV | Molecular Surface Viewer |
| MSW | Mikheev - Smirnov - Wolfenstein |
| MSWM | Matched Six Wave Mixing |
| MT | Mechanical Transfer |
| MT | Multiple Transformations |
| MT | Multiverse Theory |
| MTD | Minimum Translation Distance |
| MTF | Magnetized Target Fusion |
| MTS | Merlin Tube Specification |
| MTS | Momentum Throttle Slide |
| MTS | Muffin Tin Surface |
| MTTF | Muon Trigger Track Finder |
| MTU | Modal Test Union |
| MTXM | Magnetic Transmission X-ray Microscopy |
| MURMEMWC | 'MURMURING MEMORIAL WATER CLOSET' PRE-DATED BY 1913 MODEL YEAR AND PATENT; aka; Ed Loud Memorial Toilet |
| MUT | Material Under Test |
| MV | Medium Voltage |