| NR | do not repeat [Lat. non repetatur]; nerve root; neural retina; neutral red; noise reduction; nonreac... |
|---|---|
| NTD | neural tube defect; nitroblue tetrazolium dye; noise tone difference; 5'-nucleotidase |
| PN | papillary necrosis; parenteral nutrition; penicillin; perceived noise; percussion note; periarteriti... |
| PNdb | perceived noise decibel |
| S/N | signal/noise [ratio] |