| Acronym | Definition |
|---|
| NNSD➣Night Night Sweet Dreams |
| NNSD➣Nearest Neighbor Spacing Distribution (physics) |
| NNSD➣NewAge Net Serial Driver |
| NNSD➣No Nonsense Self-Defense (crime prevention) |
| NNSD➣Nearest-Neighbor Standard Deviation (spatial dynamics) |
| NNSD➣National No Smoking Day (UK and Ireland) |