| NN | Neoplastic nodules |
|---|---|
| NN | Neural Network |
| NN | Neuromedin N |
| NNA | N omega-Nitro-L-arginine |
| NNA | N(G)-nitro-L-arginine |
| NNBC | node negative breast cancer |
| NNDSS | National Notifiable Disease Surveillance System |
| NNE | non-neuronal enolase |
| NNH | number needed to harm |
| NNI | non-nucleoside inhibitor |