Green’s Dictionary of Slang

gear n.

also geer, gere
[14C+ SE gear, accoutrements]

1. [late 15C+] an object or objects; things, varying as to context.

2. [early 16C–mid-18C; 1970s+] the male genitals; thus [17C] gear-itch, lecherousness.

3. [mid-16C–early 18C; late 19C] the female genitals.

4. [1930s–70s] (US prison) a homosexual.

5. [1950s+] stolen property.

6. [1950s+] (US) an important or influential person [ SE 16C–18C].

7. [1950s+] (drugs) drugs, esp. cannabis, heroin.

8. [1960s] in the sex industry, photographs, magazines, films etc.

9. [1970s+] (W.I.) in pl., one’s best clothing.

10. [1970s+] the equipment used in sado-masochistic sex.

11. [2000s] (US black) one’s personal space.

12. [2010s] a pretty girl.

In compounds

gear box (n.)

[1970s] (Can. prison) a prison homosexual.

gearhead (n.) [-head sfx (4)]

1. [2010s] (UK drugs) a narcotics addict; also attrib.

2. see also SE compounds below.

gear job (n.) [job n.2 (2)]

[1970s] (US prison) a homosexual.

In phrases

ace gear (n.) [ace adj. (1) ]

[1960s+] (US gay) a sexually experienced homosexual man, capable of both active and passive roles.

drop one’s gear (v.) (also drop the gear)

[1950s+] (Aus./N.Z.) to undress.

gear up (v.)

[1990s+] (US black gang) to get dressed in one’s gang clothes.

in one’s gears (adj.) [late 17C–early 18C]

ready to get to work.

out of one’s gears (adj.)

[late 17C–early 18C] unsettled, out of sorts.

pack the gear (v.)

[1970s] (US) to achieve a given standard; lit. to ‘carry the equipment’.

that’s (the) gear

[1920s+] (orig. milit.) a general term of approval, ‘that’s the stuff’.

SE in slang uses

In compounds

gearhead (n.) [mechanical sense of SE gear + -head sfx (3)]

1. [1970s+] (orig. US campus) an engineering student, someone mechanically minded; thus ext. to one who is obsessed with automobiles.

2. [1990s+] (US) a car factory worker.

3. see also sl. compounds above.

gear-lever (n.)

[2000s] (S.Afr. gay) the penis.

In phrases

get oneself in gear (v.) (also put it in gear)

[1980s+] (US) to get going, to get busy.

just the gears

[1940s] ideal, perfect, exactly what is wanted.

throw one’s gears in (v.)

[1930s] (US black) to leave quickly.