Green’s Dictionary of Slang

1. a pint or quart measure of liquor, thus a pot of that size.

a.1790		H.T. Potter New Dict. Cant (1795) n.p.: upright a quart or pint pot.
1809		G. Andrewes Dict. Sl. and Cant.
1835		G. Kent Modern Flash Dict. 35: Uprights – alehouse pots.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].
1852		Kendal Mercury 17 Apr. 6/1: He ’peers to be [...] fly, for he vanted to vill me out the tape (gin) in a dinged upright (measure).
1859		Matsell Vocabulum.

2. (also uprighter) sexual intercourse performed while standing up.

c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Upright, a three penny upright. A Lady of easy vertue who for that sum, gratifies her customers standing against a wall.
1788		implied in threepenny upright under threepenny adj.
1834		‘The Upright’ in Flash Minstrel! in Spedding & Watt (eds) Bawdy Songbooks (2011) I 100: The clerk, how to please her, he well knew the way, / He behaved very upright with her every day / [...] / ‘To hold up the church I have always been glad, / So an upright each day in the chapel I’ve had!’.
1842		‘The Swell Coves Alphabet’ in Nobby Songster 29: U. is an uprighter or hunt with hasty dressing.
1870		Cythera’s Hymnal 56: A horizontal was once her delight now, / She can do all the fingering right now, / But the young bitch does say. / To me t’other day, / ‘I should like for to have an upright now!’.
1882		Cremorne I 21: I’ll go and have a cheap uprighter, / And fancy Poll’s Jemima C.
1888–94		‘Walter’ My Secret Life (1966) I 169: Her height made an uprighter easy, her quim did not seem to need so much wetting as usual.
1965		L. Dunne Goodbye to The Hill (1966) 110: It wasn’t really what you could call dancing, it was more like a dry upright.

3. a cheap bed, rented out for 3d or 4d.

1821

‘An Amateur’ Real Life in London II 164: The upright is a wretched semblance of a bed, at the rate of three-pence or four-pence; but the lofty aspirant to genteel accommodation, must put down a tester.