Green’s Dictionary of Slang

flaybottomist n.

a schoolmaster.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
c.1850		Duncombe New and Improved Flash Dict.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.