Green’s Dictionary of Slang

1. (Aus./US) to hit.

1969		D. Pendleton Executioner (1973) 153: You’re not giving them cops much to zot on to.
1976		D. Ireland Glass Canoe (1982) 24: He [...] lifted the old man off the old woman and zotted him on the chin.

2. (orig. US) to move quickly; thus zot along, zot down etc.

1984

Partridge DSUE (8th edn) 1372/1: since ca. 1965.

3. (Aus.) to act in a speedy manner, to do something abruptly, e.g. down a drink.

1976

D. Ireland Glass Canoe (1982) 14: Trouble is, you get used to zotting down schooners and you try to drink spirits the same way.