English abbreviations from fire to fish
- FIRE (Fight, Intensity, Relentless, Excellence)
- FIREFLEX (Flexible Fire Support System)
- FIRES (Fever Induced Refractory Epilepsy Syndrome or Febrile Infection-Related Epilepsy Syndrome)
- FIREX (Fire Exercise)
- FIRM (Floating Integrated Rail Mount)
- FIRS (FORSCOM Issue Resolution System)
- FIRST ((observing program) Faint Images of the Radio Sky at Twenty-centimeters, a radio survey of the sky with the Very Large Array)
- FIS (Fuze Interface System)
- FISA (Fédération Internationale des Sociétés d'Aviron (French, "International Federation of Rowing Associations"))
- FIS-B (Flight information services – broadcast)
- FISC (Fleet and Industrial Supply Center)
- FISH (Fighting In Someone's House (UK) (Colloquial. Slang term for FIBUA))