A cruel sport practised at wakes and fairs, in the following manner: A cock sparrow whose wings are clipped, is put into the crown of a hat; a man having his arms tied behind him, attempts to bite off the sparrow’s head, but is generally obliged to desist, by the many pecks and pinches he receives from the enraged bird.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Mum Glass * MummerNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes