Green’s Dictionary of Slang

belt n.

[lit. and fig. uses of belt v. (1)]

1. [mid-19C+] a blow, a hit, a punch; also fig.

2. [late 19+] a drink of, a swig or swallow of, e.g. a belt of coffee.

3. [1930s+] (drugs) the immediate effect of a drug, usu. one that has been injected.

4. [1930s+] a thrill.

5. [1940s] (US) the immediate effect of a drink of alcohol.

6. [1940s–60s] a measure of marijuana or any other drug.

7. [1940s–60s] an act of sexual intercourse.

8. [1950s] (Aus.) a prostitute.

9. [1950s] a sexually appealing woman.

In phrases

belt of the crozier (n.)

[1970s+] (Irish) a reprimand from the Church, spec. from a bishop.

give someone the belt (v.) (also give someone the Lonsdale) [the Lonsdale belt; thus a pun on belt v. (1); the belt itself, given to a boxing champion, is named for Hugh Cecil Lowther (1857–1944), 5th earl of Lonsdale]

[1930s+] (orig. Aus.) to get rid of, to throw out, to dismiss, to reject, to jilt.

SE in slang uses

In phrases

below the belt (adj.) [boxing use, which declares such blows as foul; 20C+ use is SE]

[late 19C] underhand, illegal, cheating.

belt up (v.) [one wraps a fig. ‘belt’ around one’s mouth]

[1930s+] (orig. RAF) to be quiet; esp. in excl. belt up! shut up!

hold the belt (v.) [boxing imagery]

[late 19C–1910s] (Aus.) to be the outstanding example, the ‘champion’.

lower one’s belt (v.)

[1960s] (US gay) to be a promiscuous ‘feminine’ lesbian.

take the belt (v.) [boxing imagery: the belt awarded to a champion]

[late 19C] (US teen) to be exceptional, to ‘take the biscuit’ .

unbelt (v.) [SE unbelt, to remove a sword]

[late 19C–1920s] (US) to hand over money.

under one’s belt (also below one’s belt)

1. [late 18C; mid-19C+] in one’s stomach, swallowed.

2. [20C+] (also under one’s vest) personally achieved or experienced.