Green’s Dictionary of Slang

(US/UK, usu. juv.) unpleasant, disgusting, with overtones of stickiness or smelliness; also used adverbially (see cit. 2004).

1969		Current Sl. IV:1 17: Yecchy, adj. Extremely unpalatable (of food or drink).
1976		N.Y. Times Mag. 21 Mar. 111: The disgusted ‘yecchy,’ with its comic-strip origins, fades, but the equally disgusted gross (ugly, objectionable, and sometimes used admiringly) shows staying power.
1977		C. McFadden Serial 93: He kept yelling about how eggplant is yucky.
1977		N.Y. Times Mag. 12 June 103: Urine tests are ‘yukky.’.
1982		H. Beaton Outside In I i: ma: Just look at you. Y’ all sticky! lou: Yukky!
1990		Eble Campus Sl. Apr. 9: yuck/yucko/yucky – distasteful, disgusting.
1998		P. McCabe Breakfast on Pluto 32: Never once [...] did I smell old yukky sweat or see some grime between two toes. [Ibid.] 132: I didn’t have any yucky briefs if that’s what you mean.
2003		Mad mag. Oct. 54: Crawley’s doing all the stupid, yucky stuff.
2004		Mad mag. Apr. 48: A jigsaw puzzle? That’s so yucky dull!
2024		J. Meades Empty Wigs (t/s) 628: Decades of fried food had left a layer of grease everywhere and had been absorbed by the yucky soft furnishings.