Green’s Dictionary of Slang

quarter n.

1. as a sum of money.

(a) [mid-18C–mid-19C] five shillings (25p), $5.

(b) [1970s] (US) $25.

2. in drug and tobacco uses.

(a) [mid-19C–1900s] (UK prison) a quarter inch of tobacco.

(b) [1960s+] a quarter ounce (7g) of a narcotic drug.

(c) [1980s+] $25 worth of a given drug.

3. as a jail sentence.

(a) [late 19C–1900s] (UK Und.) a three-month’s prison sentence.

(b) [20C+] (US Und.) a 25-year prison sentence.

In compounds

quarter house (n.)

[1970s] (US drugs) a place where drug users can obtain quarter-ounces of narcotics.

In phrases

half-quarter (n.)

[1980s+] (US drugs) one-eighth of an ounce (5g) of cannabis.

SE in slang uses

In phrases

who put the quarter in your slot?

[1980s+] (US campus) a sarcastic admonition to mind one’s own business.