- F1 hybrid
- Formula One / Formula 1
- (weather) A rating of F1 on the Fujita scale
- a computer keyboard key, short for function 1.
- (slang, dated) help or advice (derived from the common usage of "F1" as the help key, during the DOS era of computing programs)
(Can we add an example for this sense?)
- Storm Prediction Center (accessed 2010-02-03), “Fujita Scale”, in (Please provide the title of the work)