Fuck

Etymology:
Tracing the history of the word ‘fuck’ is quite hard because it was considered so reprehensible during the middle ages that people rarely wrote it down. The likelihood is that it comes from the old German ‘fricken’ to strike or ‘foch’ to plough. In the 17th Century, roustabout poet and degenerate aristo Earl of Rochester was the first to use it with the spelling we favour now.

Essential use in cinema: Blue Velvet
The biggest tip-off that Frank Booth is utterly demented is his foul language, to the extent that the colour in the title becomes very appropriate to the feel of the film. The first time we see the deranged, amyl sniffing cretin he unleashes a Blitzkreig of Tourettes: “Fuck you, you fucking fuck. Fuck you, you fucking fuck! You fucking fuckers fuck!”