| LPFN | low-pass filtered noise |
|---|---|
| MNA | maximum noise area |
| NAC | N-acetylcysteine; National Asthma Center; National Audiovisual Center; Noise Advisory Council |
| NC | nasal cannula; nasal clearance; neck complaint; neonatal cholestasis; neural crest; neurologic check... |
| NF | nafcillin; National Formulary; nephritic factor; neurofibromatosis; neurofilament; neutral fraction;... |