| Acronym | Definition |
|---|
| FRU | Field Replaceable Unit |
| FRU | Fiji Rugby Union |
| FRU | Free Representation Unit (est. 1972; UK) |
| FRU | Force Research Unit (British Army) |
| FRU | For Reasons Unknown |
| FRU | Front Row Union (fan club; UK) |
| FRU | Fonds pour le Renouvellement Urbain (French: Urban Renewal Funds) |
| FRU | Federal Reserve Unit (Malaysia) |
| FRU | Full Retail Upgrade |
| FRU | Bishkek, Kyrgyzstan - Bishkek Airport (Airport Code) |
| FRU | Freshwater Research Unit |
| FRU | Fire Rescue Unit |
| FRU | First Responder Unit |
| FRU | Field Research Unit |
| FRU | Fisheries Research Unit |
| FRU | Flat Rate Unit (automotive) |
| FRU | Florida Rugby Union |
| FRU | Frequency Reference Unit |
| FRU | Fuselage Refueling Unit (air to air refueling) |