Green’s Dictionary of Slang

cockstand n.

[cock n.3 (1) + SE stand]

an erection; thus phr. this will give you the cockstand; cockstanding adj., sexually arousing.

[UK] ‘Sub-Umbra, or Sport among the She-Noodles’ in Pearl 4 Oct. 5: She made us do it over and over again and, when we were exhausted, sucked our pricks up to renewed cockstands.
[UK]‘Walter’ My Secret Life (1966) I 19: I had no cock-stand, and am sure that I then did not know that the woman had a hole called a cunt. [Ibid.] X 2153: The two splendid creatures formed a most voluptuous spectacle — a cockstanding sight.
[Ire]Joyce letter 6 Dec. to Nora Barnacle in Ellman Sel. Letters (1975) 184: The smallest thing gives me a great cockstand.
[UK]K. Amis letter 23 Jan. in Leader (2000) 363: Kingsley Amis’s uproarious, side-splitting, tear-jerking, cock-standing etc.
[UK] (ref. to c.1917) E. Williams Emlyn 197: I passed a dozen Highlanders [...] fast asleep, knees up to the chin [...] the kilts had ridden up over their bellies and the summer dawn was kissing a row of the biggest cock-stands anybody’s ever set eyes on.
[UK]A. Salkey ‘I into history, now’ Jamaica (1983) 9: You see all them / rass gal jus’ givin’ / all o’ we cock-stan’.
[SA](con. 1976) B. Simon ‘Black Dog’ Born in the RSA (1997) 8: You get a cockstand if you see an advert for stockings on the side of a bus even.
[US]H. Rawson Dict. of Invective (1991) 88: cock-stand. An erection.
[SA]A. Lovejoy Acid Alex 170: I can see he has a moerse cockstand.