Green’s Dictionary of Slang

1. (Aus.) a child, usu. a white child.

1887		‘Aus. Colloquialisms’ in All Year Round 30 July 67/2: ‘Joey’ is a familiar name for anything young and small, and is applied indifferently to a puppy, or a kitten, or a child.
1898		E.E. Morris Austral Eng. 223/1: Joey (2) slang used for a baby or little child.
1955		D. Niland Shiralee 27: Got a joey with yer, have yer? And what’s your name, young ’un.
1968		S. Gore Holy Smoke 42: Until along comes young Daniel, not much more’n a joey at the time, but pretty shrewd for his age.

2. (Aus.) a sodomite, an active male homosexual.

1900–10		Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 88: JOEY: Aust. vulgar an hermaphrodite, or sodomite; applied generally to any foppish or effeminate young man.
1966		Trimble 5000 Adult Sex Words and Phrases.

3. (Aus.) a worthless cheque; like the animal, it ‘bounces’.

1943

Baker Popular Dict. Aus. Sl. (2nd edn).

4. (Aus. gay) a young male prostitute or the young lover of an older man.

1972		B. Rodgers Queens’ Vernacular 118: Joey (Aus hetero sl, fr Aus Joey = baby kangaroo) boy erotically fostered by an older guardian.
1979		Maledicta III:2 220: Similar terms, such as joey (from the baby kangaroo, a small thing ‘in your pocket’) from Australia [...] may be more localized.

5. a fool, an ineffectual person.

1985

‘Jennifer Blowdryer’ Modern English 10: In England a lot of words mean jerk, including cunt, wally, gaylord and joey .