Green’s Dictionary of Slang

gash n.1

[as simple anatomy in the 18C, e.g. Burns c.1786: ‘The lasses they hae wimble-bores [i.e. small holes] / The widows they hae gashes’; but 20C+ use is derog. thus poss. augmented by gash adj.]

1. [late 18C+] the vagina.

2. [mid-19C–1960s] (US) the mouth.

3. [1910s+] a collective term for women as sex objects, i.e. offering the potential for sexual intercourse.

4. [1910s+] any girl or woman, incl. a prostitute.

5. [1950s+] (US) an effeminate, passive homosexual.

6. [1970s+] (US gay) the anus, in the context of sodomy.

In compounds

gash-eater (n.) [SE eater but note eat v. (4)]

[1940s+] one who performs cunnilingus.

gash-grinder (n.) [grind v. (1a)]

[1990s+] (US) a promiscuous woman; thus a general derog. term for a woman.

gash guzzler (n.)

[1970s] a cunnilinguist.

gash-hound (n.) (also gashman) [-hound sfx]

1. [1910s–60s] (US) a womanizer.

2. [1950s+] (US prison) an older homosexual man with a taste for young men or boys.

gash-mag (n.)

[1990s+] a pornographic magazine.

In phrases

flash one’s gash (v.)

[1990s+] (Aus.) of a woman, to expose her vagina as an incitement/invitation to intercourse.

grease the gash (v.)

[20C+] of a woman, to masturbate.

rubber gash (n.) [1980s+]

1. a fake ‘vagina’ sold as a masturbation aid.

2. (also rubber cunt) a term of abuse.