Definition of foo fighter in US English:

foo fighter


  • An unidentified flying object of a kind reported by US pilots during World War II, usually described as a bright light or ball of fire.

    • ‘Some RCAF buddies talk about the foo fighters they saw over Europe in the last real war.’
    • ‘The above is a typical example of an encounter with a ‘foo fighter.’’


1940s: from ‘Where there's foo there's fire’, a nonsense catchphrase from the US Smoky Stover cartoon strip.


foo fighter

/ˈfo͞o ˌfīdər/