To talk like an apothecary; to use hard or gallipot words: from the assumed gravity and affectation of knowledge generally put on by the gentlemen of this profession, who are commonly as superficial in their learning as they are pedantic in their language.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Apostles-1 * Apothecary’s BillNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes