Green’s Dictionary of Slang

prize adj.

absolute, complete, utter; often as prize package under package n.

1896		Ade Artie (1963) 55: Say, you must think I’m a prize gilly to set around here and give up my insides to you about her.
1900		Bulletin (Sydney) 22 Dec. 11/3: Some prize idiot lately wrote to Sydney D. T. advising a sixpenny subscription from every adult in the Australias to purchase an ‘ironclad’.
1912		Ade Knocking the Neighbors 203: He is a prize Bunk, a two-handed Grafter, a Short-Change Artist and a Broadway Wolf.
1920		H.C. Witwer Kid Scanlon 80: The prize boob of the country is waterin’ the pavement around his real estate.
1924		P. Marks Plastic Age 226: He was known all over the campus as a ‘prize sucker’.
1934		P. Allingham Cheapjack 211: Lord! you were a prize mug in those days.
1940		J.G. Brandon Gang War 131: What do you think of that prize rat, Drucci, being closeted here with Schurtz?
1951		J.D. Salinger Catcher in the Rye (1958) 90: I certainly began to feel like a prize horse’s ass, though, sitting there all by myself.
1960		(con. c.1928) D. Holman-Hunt My Grandmothers and I (1987) 160: In my humble opinion your Papa, as you call him, is a prize silly ass!
1975		C. Dexter Last Bus to Woodstock 184: I said they’re a pair of prize liars.
1981		S. Berkoff Decadence in Decadence and Other Plays (1985) 11: I never got nothing / a prize nitwit.
1985		‘Thommo’ Dict. Aus. Swearing & Sex Sayings 101: PRIZE CUNT — A person similar to a low arse, who has no consideration for other people [...] PRIZE PRICK — Similar to an arsehole or dead shit.
1990		T. Winton Human Torpedo 94: You’re really a prize wally.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 153: [G]ood ole George Wexford ‘Choko’ McGruder, regarded by most as a prize aleck.

In compounds