Green’s Dictionary of Slang

crank n.2

[SE crank, lively/crank (up), i.e. to crank up one’s bodily ‘motor’]

1. [late 18C–mid-19C] gin and water.

2. [1960s+] (drugs) any form of amphetamine drug, e.g. amphetamine sulphate, methedrine, methamphetamine.

3. [1970s+] a thrill of excitement, esp. when drug-generated.

4. [1980s+] (drugs) crack cocaine.

5. [1990s+] heroin.

In compounds

crankhead (n.) [-head sfx]

[1990s+] (US drugs) a regular user of amphetamines; also attrib.

In phrases

bathtub crank (n.)

[2010s] illicitly manufactured methamphetamine.

cranked (out) (adj.) (also cranked up)

[1980s+] under the influence of amphetamine or crack cocaine.