Green’s Dictionary of Slang

pushing school n.

a brothel.

c.1632		A. Brewer Countrie Girle Act I: ‘I am no man of the sword; – I have no weapon.’ ‘What should you do in Cupids fencing Schoole, And have no weapon?’.
1641		J. Johnson Academy of Love 79: This is, said Cupid, our Fencing Schoole [where] men shall fence against women, who although they chance to make a thrust gainst these weaker vessels, and pierce them at least two handfull deepe, yet the wound is not mortall.
c.1698		B.E. Dict. Canting Crew n.p.: Pushing-school [...] a Bawdy-house.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1793		J. Caulfield Blackguardiana.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.