Green’s Dictionary of Slang

1. (also cam, cammy) a camisole or underbodice.

1984

Partridge DSUE (8th edn) 176/1: cami [...] ; [...] also cammy and cam .

2. cami-knickers.

1977

S. Berkoff East in Decadence and Other Plays (1985) 77: He’d be fumbling with my cami, my cami-knickers that is.