| Abbreviation | Definition |
|---|---|
| NRRV | New River and Roanoke Valleys |
| NSE | Natures Sea Essentials |
| NSGI | National Standards for Geographic Information |
| NSL | Nevada Seismological Laboratory |
| NSQ | Natural Stone Quarry |
| NSSC | National Soil Survey Center |
| NSU | Northern Superior Uplands |
| NSZ | Nyainqentanglha Shear Zone |
| NUAP | Northern Unglaciated Allegheny Plateau |
| NVGD | Niging Van Grammofoonplaten Detaillisten |
| NVM | National Volcanic Monument |
| NVOSC | No Visual/Olfactory Signs of Contaminants |
| NVZ | Northern Volcanic Zone, Iceland |
| NWL | North Wales Limestone |
| NWMO | Nuclear Waste Management Organization |
| OASIS | Open Accessible Space Information System |
| OBE | Operating Basis Earthquake |
| OBGYN | Obstetrics and gynaecology |
| OBM | Oil-Based Mud |
| OBT | Orange Blossom Trail |