cavvy, n. — Green’s Dictionary of Slang

cavvy n.

[? SE caviar, the reference is presumably to its cost and quality rather than to its fishiness]

1. (also cavi) marijuana.

1993

Dr Dre ‘187’ 🎵 Nuts full of cavi and I’m headed for the bar.

2. (also cavy) crack cocaine.

1991		L. Bing Do or Die (1992) 63: I sell Yay-o, Cavvy – caviar crack.
1997		M. Corwin Killing Season 109: Later, some ten-year-old kid [...] says to me, ‘Hey, homie, I got some cavy [caviar] rocks at a sweet price’.