F

   flick

   Nearly always for the verb as an expletive.

   Also as the F word:

    I thought Johnny Rotten of the Sex Pistols was going to butt my head: I said 'Lovely to see you, Mr Rotten.' He said 'F off, f face.' (newspaper report, 2000)

    The 'f ' word was broadcast on Radio 4 yesterday. {Daily Telegraph, 12 January 1995)

   And see effing.