Green’s Dictionary of Slang

1. (US black) liquor [ety. unknown; ? the squeezing of grapes].

1970

Current Sl. V:2.

2. (drugs) phencyclidine [ety. unknown].

1992

Bentley & Corbett Prison Sl. 51: Squeeze also Mr. Whipple and Bomb Expressions used in reference to the drug PCP that has been mixed with embalming fluid.