| Acronym | Definition |
|---|
| NIWA➣Nintendo Independent Wiki Alliance |
| NIWA➣National Institute of Water and Atmospheric Research, Ltd (New Zealand) |
| NIWA➣Naval Information Warfare Activity |
| NIWA➣Namibian Information Workers' Association |
| NIWA➣North Island Woodlot Association (British Columbia, Canada) |
| NIWA➣Northwest Indiana Woodworkers Association (est. 1990) |
| NIWA➣National Internet Wrestling Association |