Green’s Dictionary of Slang

1. (Aus./US) a weakling, a fool; thus quince-head.

1908		K. McGaffey Sorrows of a Show Girl Ch. xi: The first act is laid in a quince plantation, and the quinces of the chorus are discovered at curtain rise picking the luscious fruit.
1914		Ade ‘The New Fable of the Intermittent Fusser’ in Ade’s Fables 54: Even the Buckingham Palace manner and the Arctic Front cannot buffalo the idle Spectator into overlooking the fact that she belongs to the genus Quince.
1918		Wash. Herald (DC) 13 Nov. 4/1: Wonder how deeply it would pain the poor simp if he knew we called him the Clown Quince?
1924		H.L. Wilson Professor How Could You! 274: That big quince three-sheeting himself all over the place.
1955		N. Pulliam I Travelled a Lonely Land (1957) 237/2: queer (quince) – somebody who is stupid.
1960		J. Boswell Ernie and the Rest of Us 75: You think you’re being brave and noble, but you’re just a big silly quince.
1969		J. Hibberd Dimboola (2000) 97: Back to Mildura, quince-head!

2. (US) of a person/situation/object, a failure.

1908		Sporting News (N.Y.) in Fleming Unforgettable Season (1981) 9: If that isn’t sure enough quince, I will admit that McGraw has more brains than all the judges in America.
1913		Wash. Times (DC) 24 July 10/5: Larry Chappell loooked like a bitter quince yesterday. he failed to hit a ball out of the infield all day.
1920		Ade Hand-made Fables 187: This Stock never had declared a Divvy, and the whole Venture was commonly regarded as a Quince.

3. (Aus./US) a homosexual, esp. one who can be both active and passive.

1966		Trimble 5000 Adult Sex Words and Phrases.
1972		B. Rodgers Queens’ Vernacular.
1999		G. Seal Lingo 114: While gay has become the accepted mainstream term, the vernacular is still full of other, less positive terms, such as [...] quince, fruit, cat, fag, fairy, ponce (also meaning pimp), punce, and the now totally out-moded homo.

4. (Aus.) the buttocks.

1999

G. Seal Lingo 115: quince, used in such phrases as you’re getting on my quince, indicating irritation, is also one of many Lingo words for the posterior or anus. This probably explains why it is also applied to homosexuals.