Green’s Dictionary of Slang

1. a medlar; occas. euph. as the anus; cit. 1732 refers to anal sex [the fruit’s large open disk between the persistent calyx-lobes].

c.1642		T. Killigrew Parson’s Wedding (1664) II ii: Yet if you be cruel, he and they die, as useless as open-arses gathered green.
1655		Mercurius Fumigosus 35 24–31 Jan. 276: A Shee-Costermonger, daughter to an Apple-Squire in Kent, which sells open Arses dead and alive.
c.1698		B.E. Dict. Canting Crew n.p.: Open-arse a Medlar.
1732		Ladies Delight 4: Others too curious will innoc / Culate their Plants on Medlars Stock, / (i.e. as Tongues in Vulgar pass, / They graft it on an Open-arse.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Medlar. A fruit, vulgarly called an open a-se; of which it is more truly than delicately said, that it is never ripe till it is as rotten as a t—d, and then it is not worth a f—t.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].

2. a prostitute [a coarse ref. to her stock-in-trade].

1595		Shakespeare Romeo and Juliet II i: Now will he sit under a medlar-tree, And wish his mistress were that kind of fruit, As maids call medlars, when they laugh alone. Oh Romeo! that she were, O! that she were An open et caetera.
1655		Mercurius Fumigosus 35 24–31 Jan. 276: A Shee-Costermonger, daughter to an Apple-Squire in Kent, which sells open Arses dead and alive.
c.1698		B.E. Dict. Canting Crew n.p.: Open-arse [...] a Lewd Woman.
1725		New Canting Dict. [as cit. c.1698].

the vagina.

1834		‘The C—’ in Flash Minstrel! in Spedding & Watt (eds) Bawdy Songbooks (2011) I 120: The C—! the C—! the open C’ / Where every man does like to be.
1837		‘The Sailor’s Yard’ in Ticklish Minstrel 32: ‘Alas! O lackaday!’ cried she, / ‘No more ’twill be popt in the open C.’ [Ibid.] 33: ‘O lor, what a yard!’ she cried, with a grin [...] And insisted that Jack should plough the wide C.
1842		Whip & Satirist of NY & Brooklyn (NY) 12 Feb. n.p.: Although to boarding used you are, / And ploughing, too, the open sea.
c.1844		Coal Hole Companion in Bold (1979) 91: The jolly tar so full of glee / Admires the tempting open C.
1880		‘The Columbine’ in Pearl 9 Mar. 25: No Roman dancer could surpass, / The way she shows her open C, / And flourishes her jutting arse.
1890–1904		Farmer & Henley Sl. and Its Analogues.

(US) a prostitute with no specific affiliation to one pimp.

1983

R. Klein Jailhouse Jargon and Street Sl. [unpub. ms.].

see fair go n.

(drugs) the intoxication one gets from breathing in ambient cannabis or crack cocaine smoke in a room, rather than actually smoking the drug directly.

1993

R. Shell Iced 169: I can’t even let the goodness collect in the air and get an open high!!!

(Aus.) a situation with no restrictions or limits to one’s wishes.

1951		E. Hill Territory 445: Open slather: A free hand.
1955		D. Niland Shiralee 209: You mean that would give her open slather?
1959		G. Slatter Gun in My Hand 180: Come round, she said, it’ll be open slather.
1965		J. O’Grady Aussie Eng. (1966) 65: If you’re goin’ out that way, call in at So-and-so’s pub. She’s open slather there on Sundays.
1988		McGill Dict. of Kiwi Sl. 79/2: open slather unconstrained and often riotous gathering available to allcomers; possibly from Irish ‘slighe’, access.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].
2007		S. Maloney Sucked In 40: Once the police ID the body, it’ll be open slather.
2018		C. Hammer Scrublands [ebook] ‘[O]nce he was gone and the place was empty it was open slather’.

see swinging n.² (1)

(US Und.) safe-breaking.

1931		Irwin Amer. Tramp and Und. Sl. 139: Open Work.–Safe-blowing.
1949		Monteleone Criminal Sl. (rev. edn).