Green’s Dictionary of Slang

1. an underage girl seen as a sex object.

1962		Truth (Wellington) 27 Nov. 13: He used to call her ‘Carny’, a popular term for anyone who had carnal knowledge and was underage [DNZE].
1971		T.R. Shadbolt Bullshit and Jellybeans 34: All these little teenybopper girls used to hang around trying to look tough, but none of the guys would touch them because they were all carnies [DNZE].
1988		McGill Dict. of Kiwi Sl. 25/2: carnie sexually desirable and probably available female under the lawful age of 16 for sexual intercourse, short for ‘carnal knowledge’; aka ‘jailbait’, because of jail sentence for male convicted of carnal knowledge.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. a young person living on the streets.

1991

Dominion Sunday Times (Wellington) 8 Dec. 9: In street lingo the younger streetlifes are called ‘younglings’ or ‘carnies’ and the older ones ‘originals’ or ‘old boys’ [DNZE].