Green’s Dictionary of Slang

1. second-rate, inferior; of food, spoilt.

1961

(con. early 1950s) J. Peacock Valhalla 20: I’m a gungy bastard.

2. sticky, messy, slimy.

1992

K. Lette Llama Parlour 49: As long as ya rinse ya plates before puttin’ ’em in the dishwasher. I hate people who just like, put ’em in all gungy.

3. revolting.

1965		E. Bond Saved Scene vi: Gungy bastard!
1976		(con. 1969) C.R. Anderson Grunts 27: They call them grunts, you now, the guys from the bush in Nam, and they’re supposed to be the gungiest mothers around.
1988		J. Healy Grass Arena (1990) 32: Hands off cocks, put on socks, you shower of gungy bastards, move yourselves.
1990		(con. c.1970) G. Hasford Phantom Blooper 111: Some gungy brass-balls son of a bitch.
2012		(con. 1980s) I. Welsh Skagboys 71: There’s a gungy taste in my dry mooth.