(1) Alan Richter. The Language of Sexuality (1987): ' Fuck is one of a group of well-known four letter words, all Anglo-Saxon, or Old English, in origin, that are uncomplicated, easy to pronounce, and monosyllabic.'
(2) Gay slogan: ' Homosexuality is not a four-letter word.'
(3) Brick Pollit (Paul Newman) to his father Big Daddy (Burl Ives) in Cat on a Hot Tin Roof (1958): ' You don't know what love is. To you, it's just another four-letter word.'