Green’s Dictionary of Slang

(US) contact with the vagina or penis, in the context of sexual exploration (cf. first base n. (1); second base under second adj.; home run n. (2)).

1948		(con. 1944) N. Mailer Naked and Dead 551: I got to third base last night.
1993–2003		Little Blue Patakha on Urban Dict. 🌐 Third Base The last base before sex, entailing contact with the main sexual regions, a handjob or a blowjob (fellatio) for guys and fingering or giving head (cunnilingus) to the girl. ‘We got all the way to Third Base on my friend’s roof when I bent down to give him his first blowjob ever.’.
2005		posting at advicechick.com 8 Nov. 🌐 We had been just hitting third base (kiss/feel).
2012		M. Lacher On the Bro’d 40: At the Englewood Hooters he [...] went to third base with a wiatress.

(N.Z.) a woman, generally, a girlfriend, who is considered plain and unexciting.

2003

McGill Reed Dict. of N.Z. Sl. 211: third beer A woman, usually a girlfriend, who is not attractive or very exciting; dull, ordinary.

see separate entries.

(US) the anus.

1992

Bentley & Corbett Prison Sl. 62: Third Eye The anus.

the peni; thus on three legs, having an erection.

[1788		Harris’s List of Covent-Garden Ladies 69: [She] is so very careful of her health, that befopre she receives her guinea, she must examine every one of her partner’s legs].
1843		Satirist & Sporting Chron. (Sydney) 25 Feb. 2/1: The hon. Attorney General wished to give his half for any benevolent purpose — [...] from what we can gather, he is only anxious to give his third (q. leg) to such charitable purposes - of that anon.
1972		R.A. Wilson Playboy’s Book of Forbidden Words.
1989		P. Munro Sl. U.
1992		Randolph & Legman Ozark Folksongs and Folklore I 452: The penis [...] often frankly called in American children’s slang, the third leg or middle leg.
2003		B. Dark Dirty Cockney Rhy. Sl. 82: Mystic Meg third leg.
2004		Guardian Rev. 6 Aug. 13: He calls it his ‘third leg.’.
2004		R.G. Barrett Rosa Marie’s Baby (2013) [ebook] Uriah ogled Tania [...] then hobbled off to the residence on three legs.
2013		F. Bill Donnybrook [ebook] Liz [...] winked at Pete and the girth of his third leg.
2016		Harlem Spartans ‘Hazards’ 🎵 She lucky if she get third leg.

(N.Z. prison) a getaway driver.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 188/2: third man n. (in a criminal job) the person who drives the ‘getaway car’.

see separate entries.

(US) a homosexual.

[1925		Variety 26 Aug. n.p.: Another exceptionally sordid phase of night life [is] what a prominent play broker calls ‘the third sex‘ [...] These girlish boys and manly women [etc] ].
1989–99		R.O. Scott Gay Sl. Dict. 🌐 third-sexers: [1930s New York] Homosexuals.

(US) a prostitute who cruised the third tiers of theatres.

1839

Wag (N.Y.) 7 Dec. 2/3: One of the saints of Dr. S---’s Church, whoat [sic] used to be a third tierer in all the southern theatres.

a large portable stereophonic tape deck/radio, particularly popular among black youths in the US and UK.

1981		Minneapolis Star (MN) 9 June 27/1: Now, whites who once disparaged the boxes with such nicknames as ‘ghetto blasters’ and ‘third world briefcases’ are flocking to buy the units.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 87: And I’ll shove that fuckin’ Third World briefcase up there [i.e. ‘your arse'] as well.
1986		Guardian 23 Feb. 27/4: A number of the portables (a.k.a. Ghetto Blasters or Third World Briefcases) are beginning to sprout extra buttons.
1987		Eble Campus Sl. Fall.
1993–2003		Urban Dict. 🌐 wog box A large stereo carried held to the ear by some tinted folk. Also 3rd world briefcase. I saw one of those new wog boxes in Dixons that puts out about 100 watts.
1992		G.P. Pelecanos Firing Offense 63: ‘What did he steal?’ ‘A third world briefcase, what else? [. . . .] He lost his job for a boogie box’.

see need like a hole in the head under hole in one’s head n.