| Acronym | Definition |
|---|
| NIRT➣Northamptonshire Ironstone Railway Trust (UK) |
| NIRT➣Nanoscale Interdisciplinary Research Teams |
| NIRT➣National Incident Response Team (Federal Reserve System) |
| NIRT➣Nuclear Incident Response Team (US DHS) |
| NIRT➣National Iranian Radio Television |
| NIRT➣Network Infrastructure Release Testing (Cingular) |
| NIRT➣National Inquiry Response Team |