Green’s Dictionary of Slang

1. (also break one’s leg) of a womanizing man, to become father to a child, whether one wishes to or not.

1828

W. Carr Dial. of Craven [Yorks.] 285: He hath broken his leg, ‘of a dissolute person on whom a child has been filiated’.

2. (also break one’s leg) to become pregnant out of wedlock; often ext. as break a/one’s leg above the knee; thus broken-leg, a single mother.

c.1621		Beaumont & Fletcher Wild-Goose-Chase IV i: She was first a Ladies Chamber-maid, there slip’d And broke her leg above the knee.
1675		Head Art of Wheedling 189: Though she hath broken her leg, she is sound enough for a Drawer, newly out of his time, who, having credit for wine, his house is furnished with the money that did set his wife’s broken leg.
1737		J. Ray Proverbs (3rd edn) 200: She hath broken her leg above the knee. i.e. had a bastard.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: leg [...] to break a leg, a woman who has had a bastard, is said to have broken a leg.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].
1908		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 294: break one’s leg, v. phr. Of a woman, to become with child illegitimately.
1925		E. Field ‘A French Crisis’ in Facetiae Americana 19: She’d break her leg above the knee, pound, click and tread as well.
1965–70, 1979		in DARE.
1960		(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 18: Broken-leg – the mother of a bastard.
1989		H. Rawson Dict. of Invective (1991) 309: Variations on this theme, all casting the event in terms of an accident, include [...] break a leg, and break a leg above the knee.

3. (also break one’s knee) of a young woman, to lose one’s virginity, to be seduced.

1896		Farmer Vocabula Amatoria (1966) 134: forligner. To copulate; ‘to break one’s knee’.
1949		Monteleone Criminal Sl. (rev. edn) 33: break a leg To be seduced; to make a woman pregnant.

4. to seduce.

1859		Matsell Vocabulum.
1881		Trumble Sl. Dict. (1890).

5. (US) to be arrested.

1908		J.M. Sullivan Criminal Sl. 4: Broke a leg – Got arrested.
1919		NY Tribune 8 June 7/5: To announce he is under arrest, he says he has ‘broken a leg’.
1924		G. Henderson Keys to Crookdom 400: Capture. Caught [...] broke a leg.

6. (orig. US) to hurry.

1915		N.Y. Eve Journal 5 Aug. 15: Tear up to 1492 Columbus and slip this wire to Mr. P.J. Flanigan – and break a leg getting back [HDAS].
1942		Berrey & Van Den Bark Amer. Thes. Sl.
1951		J.D. Salinger Catcher in the Rye (1958) 63: I could picture her breaking a goddam leg to get to the phone and tell my mother I was in New York.
1970		G. Cain Blueschild Baby 119: Niggers just so weak, break a leg getting next to one of them tramps [i.e. white girls].