Green’s Dictionary of Slang

a schoolmaster.

1771		Foote Maid of Bath in Works (1799) II 230: poultice: Wasn’t you under old Syntax at Wells? flint: He died the year I left school.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1859		Matsell Vocabulum.
1862		E. de la Bédollière Londres et les Anglais 318/1: syntax, un maître d’école.
1895		Crowe Aus. Sl. Dict. 83: Syntax, a schoolmaster.