Green’s Dictionary of Slang

1. (Aus.) a measure or ‘shot’ of hard liquor.

1910

Bulletin (Sydney) 13 Oct. 19/3: Removing the cork with her teeth, she poured us out a good stiff nip or ‘bite’ – as a matter of fact, it bit like a bull-hound suddenly propelled from the end of a hot poker.

2. (US drugs) a small measure of drugs.

1935

A.J. Pollock Und. Speaks 1/1: A bite, a small quantity of dope.