Green’s Dictionary of Slang

1. the anus.

1533		J. Heywood Play of Weather in Farmer Dramatic Writings (1905) 129: And if this tale be not likely / You shall lick my tail in the nock.
c.1650		Le Strange Merry Passages and Jeasts No. 459 127: In an Extreame sharpe Frost, mens Noses began to Mortifie upon their Faces; [...] there was no way thought so sure for their Preservation, as alternis vicibus to couch them in one anothers Nocks.
1653		Urquhart (trans.) Gargantua and Pantagruel (1927) I Bk I 53: Of all [...] bunghole cleansers and wipe-breches, there is none in the world comparable to the neck of a goose, that is well downed, you will thereby feel in your nockhole a most wonderful pleasure.
a.1661		‘The Rump Carbonado’d’ Rump Poems and Songs (1662) II 85: Lenthall now Lords it though the Rabble him mock, / In calling him Speaker, and Speaker to the Dock, / For an hundred pound more hee’l kiss their very Nock.
1672		J. Phillips Maronides (1678) VI 102: But Switzer bids her kiss his nock.
1675		C. Cotton Scoffer Scoff’d (1765) 282: Twixt some twelve and one o’clock, He tilts his Tantrum at my Nock.
1682		Mennis & Smith et al. ‘On a Fart’ Wit and Drollery 146: And my Stomach begins to grumble, Which makes me think that Farts ere long Will at my Nock soon find a tongue.
1775		J. Ash Dict. Eng. Lang.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1872		C. Hindley Old Book Collector’s Misc. 9: nock. — The posteriors.

2. the vagina [Cotgrave (1611) suggests backslang: ‘Noc. Con, Turned backward (as our Tnuc) to be the lesse offensive to chast eares.’].

1598		in Florio Worlde of Wordes n.p.: Cunno, a womans priuie part. Cunnuta, a woman nocked.
1611		Florio Queen Anna’s New World of Words n.p.: Cunno, a womans nocke or priuy parts.
1613		Middleton Chaste Maid in Cheapside I i: sir walter: Here you must pass for a pure virgin. davy [Aside] Pure Welsh virgin, she lost her maidenhead in Brecknockshire [i.e., ‘break-nock-shire’].
1658		Mennis & Smith ‘The Same to the Same’ Wit Restor’d (1817) 124: Some one Il’e marrie that’s thy Neece / And Livings have with Bellie-peece, / This some call Symonie oth’smock, / Or Codpeece, that’s against the Nock.
a.1674		Rochester ‘The Argument’ Poems on Several Occasions (1680) 37: Thus was I Rook’d of Twelve substantial Fucks, / By these base stinking, over itching Nocks.
1681		Scudamore Homer Alamode Pt 2 i 5: Calypso ... put off Boddis And Petticoat, nay, and fine Smock, And there she shew’d her dainty Nock.
1925		E. Field ‘A French Crisis’ Facetiae Americana 19: What shall I term that slimy pit-like orifice of sin, / [...] / A– tuppence, twitchet, coney, commodity or nock.