Green’s Dictionary of Slang

a euph. for fuck n. in all senses.

1948		(con. 1944) N. Mailer Naked and Dead 10: What the fug do ya think I got. [Ibid.] 212: Where the fug is the souvenirs? [Ibid.] 284: Bunch of fug-ups, lose a godam gun.
1958		(con. 1940s) B. Behan Borstal Boy 43: He would shove me into chokey [...] wearing fugh-all.
1961		R. Gover One Hundred Dollar Misunderstanding 21: I don’ know jes where the fug he thinks he is at.
1962		(con. 1940s) H. Simmons Man Walking On Eggshells 115: Man, who the fugg said anything to you?
1989		B. Reed ‘Messman on C.E.’s Altar’ in Passing Strange (2015) 22: ‘Look at this spill! Who the fugg’s gonna clean it up’.
2001		M. Bracewell Perfect Tense 57: They [...] spoke in a strange new language of acronyms and initials – ‘FUG’, ‘TUK’ and ‘HURL’ were my favourites.
2004		(con. 1960s-70s) T. Taylor Top Fellas 66/2: No one gave a rusty fug.