| NAKED KARST | Syn. Bare karst. Karst - Kinds of. Ref WM |
| NATURAL ARCH | An arch of rock formed by weathering. Speleology term. Ref JJ |
| NATURAL BRIDGE | A bridge of rock spanning a ravine or valley and formed by erosive agents. Speleology term. Ref JJ |
| NECROPHAGE | A scavenger feeding on animal carcasses rather than live prey. Cave - Biota. Ref JJ |
| NETWORK | A complex pattern of repeatedly connecting passages in a cave. Syn Maze, cave, Labyrinth. Speleology term. Ref JJ |
| NICHE | An organism's place in the cave ecosystem. Where it lives and eats, and what eats it. How it interacts with all biotic and abiotic factors. Fauna. Ref AC |
| NIFE CELL | A rechargeable alkaline battery for use with an electric cap lamp. Lighting term. Ref JJ |
| NORTHING | 1. The distance of a point north of the point of origin of the grid of a map. 2. The south-north component of a survey leg, or of a series of 2 or more legs. North is positive, south is negative. cf Easting. Survey & Mapping term. Ref JJ |
| NOTHEPHREATIC | Referring to water moving slowly in cavities in the phreatic zone. Speleology term. Ref JJ |
| NUMBERING | Assigning an alphanumeric identity number to a cave entrance, such that no 2 entrances have the same number. Survey & Mapping term. Ref JJ |
| NYMPH | Some insect young or juveniles are called nymphs. Esp. those with no or incomplete wings. Fauna. Ref AC |