clue, n. — Green’s Dictionary of Slang

clue n.

[? link to SE clue, an aggrandizement of things, thus used euph.]

1. (Scot.) the vagina.

c.1800

‘The Reels o’ Bogie’ in Burns Merry Muses of Caledonia (1965) 154: By bobbing on my wanton clue, / You see your pintle’s all on fire.

2. (Aus.) a woman.

1913		Sport (Adelaide) 7 June 12/2: Jim P. [...] Thinks he’s on a clue. He would get a knock back if he knew the girls had him by the leg.
1920		Advocate (Burnie, Tas.) 5 June 7/2: The silly poon’s gone dopey about that clue he’s pirating.
1920		Sun. Times (Sydney) 29 Feb. 18/4: Gor’ blime, blokes, it’s all serene, / I’m starrin’ on the pitcher screen. / Old boshter Bill is wiv me, too. / And wiv ’im is Doreen, his clue.
1945		Baker Aus. Lang.

3. (US campus) a stupid person.

1991

Eble Campus Sl. Mar. 2: clue – someone who is not aware of what’s going on.

get a clue (v.) [SE colloq. phr. not have a clue]

1. (US black) to become aware.

1983		Eble Campus Sl. Mar. 3: get a clue – get smart and aware.
1985		Indianapolis Star (IN) 10 Feb. 5G/2: Get a clue (NC) - an admonition directed at one who is not current or not paying attention; same as get a life.
1992		D. Burke Street Talk 2 16: Get a clue!

2. (US campus) to think sensibly or logically, to not be stupid or naïve.

1981		Eble Campus Sl. Fall 3: get a clue – pay attention, get the right information.
1996		Eble Sl. and Sociability 56: The verb phrases get a clue, get a grip, get a job, get a life, get with the program all mean ‘act in an aware or responsible manner’.