who carries his flag on the main-mast. A landlord or publican wearing a blue apron, as was formerly the custom among gentlemen of that vocation.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Addle Plot * Admiral of the Narrow SeasNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes