| Abbreviation | Definition |
|---|---|
| NV | No Vacuum |
| NVD | Noise & Vibration Detection |
| NVH | Noise Vibration Harshness |
| NWAP | New Worlds in Astroparticle Physics |
| O | Ohm |
| OACC | ordered amorphous carbon clusters |
| OASIS | Optically Adaptive System for Imaging Spectroscopy |
| OBDM | One-Body Density Matrix (nuclear physics) |
| OBDM | Optical Beam Deflection Method (physics) |
| OBM | Over-the-Barrier Model |
| OBQ | Optimize Beam Quality |
| OC | Old Coherence |
| OCMEs | Overexpanding Coronal Mass Ejections |
| OCQ | Old Covariant Quantization |
| OCS | On-Chip Spectroscopy |
| OCS | Optical Calibration Sphere |
| OD | Originally Detectable |
| OD | Other Dimension |
| ODCR | Optical Detection of Cyclotron Resonance |
| ODCR | Optically Detected Cyclotron Resonance |