Green’s Dictionary of Slang

pushing school n.

also fencing school
[push v. (1) + SE school. Note SE pushing school, a fencing school, thus link to the sl. uses of dagger n.1 and other synons. meaning the penis]

a brothel.

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?’.
[UK]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.
[UK]B.E. Dict. Canting Crew n.p.: Pushing-school [...] a Bawdy-house.
[UK]New Canting Dict. [as cit. c.1698].
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]J. Caulfield Blackguardiana.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.