Green’s Dictionary of Slang

1. badges, medals.

1946		J.W. Bishop ‘Amer. Army Speech’ in AS XXI:4 Dec. 246: Ribbons representing decorations and campaign medals were sometimes called fruit salad, but I have never known them to be called brag rags except in the funny papers.
1952		(con. 1944) Wilder & Blum Stalag 17 [film script] 33: You can be the heroes, the boys with the fruit salad on their chest.
1960		(con. 1940s) D. MacCuish Do Not Go Gentle (1962) 376: Where’d ya get the fruit salad, cousin? My, my, the Purple Heart, too.
1971		B. Moyers Listening to America 142: A highly decorated fellow who didn’t have any more room for fruit salad on his chest.
1989		Hackworth & Sherman About Face (1991) 212: Fresh-faced Lieutenant Combats whom the class’s collective fruit salad would have had shitting for a year.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] ‘What’s all that fruit salad for? Conspicuous gallantry in seat-warming?’.

2. (US drugs/teen) a random combination of any pills or capsules of drugs available, including psychotropic and medicinal, on which to get intoxicated.

1969		R.R. Lingeman Drugs from A to Z (1970) 98: fruit salad Among teen-agers, a game in which each participant takes one pill from every bottle found in the family medicine cabinet.
1971		Current Sl. V:4.

3. (S.Afr. gay) the male genitals [presumed resemblance to a banana and apples].

2003

K. Cage Gayle.

4. (N.Z. prison) a mixture based on morphine sulpahte tablets, from which morphine can be extracted.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 75/1: fruit salad n. a concoction of various MSTs, cooked up (prepared in order to extract the morphine).