| Abbreviation | Definition |
|---|---|
| NR | non-reactive |
| NR | non-reducing |
| NR | non-resistance |
| NR | non-response |
| NR | normal response |
| NR | nuclear receptor |
| NR | nuclease resistant |
| NR | nutrient restriction |
| NRE | negative regulatory element |
| NRE | non-recurring expenditure |
| NRE | norepinephrine |
| NRF | negative regulatory factor |
| NRF | Neurosciences Research Foundation |
| NRL | National Reference Laboratories |
| NRL | nucleosome repeat length |
| NRL | nucleus reticularis lateralis |
| NRLS | National Radiological Protection Board |
| NRR | nasal respiratory resistance |
| NRR | net reproduction rate |
| NRT | nucleus reticularis |