Green’s Dictionary of Slang

1. a euph. for the vagina.

1606		P. Holland (trans.) Suetonius’s Historie of Twelve Caesars (1899) I 206: [T]his infamous and shamefull Note, received with exceeding great accorde, was rife and currant abroade in everie mans mouth, That the old bucke-goat was licking the nature of the does (or females).
1775		‘Miss Jenny Kilpatrick’ in Ranger’s Impartial List of the Ladies of Pleasure in Edinburgh n.p.: She was at first frightened of the dart; but as she is now thoroughly aquainted with it, she will hug and kiss it, and put it nearest her heart, even in the very centre of nature.

2. the penis; semen.

1704		in B. Capp When Gossips Meet (2003) 243: On another occasion, she deposed, he had assaulted her in a stable, pulled up her clothes ‘and did then spend his nature upon my thighs’.
1754		Trial of Elizabeth Canning in Howell State Trials (1816) 509: Do you remember Mrs. Mayle's observation?—I do; that was, that she would take her oath that no man ever lay with her, for if there had, there would have been nature on one side or other.
1835		‘The Rakish Gentleman’ in Knowing Chaunter 44: It costs me full two pound a month / For inexpressibles; / Because my nature wears them out / While looking at the belles.
1965		H. Williamson Hustler 66: She jumped out of all her clothes, and my nature really rose when I saw her like that! But when I got in the bed, my nature fell.
1977		A. Brooke Last Toke 77: The statement was cut short by his stiffening nature poking its way greedily into her bruised mouth.
1980		J.L. Gwaltney Drylongso 161: How many men will admit that they throw their nature down the toilet.

3. one’s libido, one’s sex-drive [note Cleland (1748-9): ‘After playing repeated prizes of pleasure, nature overspent, and satisfy’d, gave us up to the arms of sleep’].

c.1500		Dunbar Tretis of the Twa Mariit Wemen line 174: He has bene lychour so lang quhill lost is his natur, / His lume is waxit larbar and lyis into swonne.
1933		(con. WWI) F. Richards Old Soldiers Never Die (1964) 106: When a man is between twenty and thirty nature rules his brain.
1946		Mezzrow & Wolfe Really the Blues 318: You take a guy thirty, forty, fifty years old, if he needs some Nature he sure can get it from marihuana.
1964		H. Selby Jr Last Exit to Brooklyn 47: Goldie filled the glass with gin, just a bit of mixer, no bennie (too much might kill his nature).
1977		A. Brooke Last Toke 204: Don’t go pawin’ an’ thinkin’ on bringin’ her back fo’ to satisfy you black-assed nature!
1980		M. Thelwell Harder They Come 328: Sometimes, when her nature come down, she jus’ had to holler one time.
1988		R.R. Moore ‘Hurricane Annie’ 🎵 Now, I know that you know the course of my nature, and I don’t mean maybe. / I make all my ho’s suck my dick cause I ain’t got time for no babies.
1997		N. Barlay Curvy Lovebox 48: My nature’s callin’.