A red silk handkerchief, intermixed with yellow and a little black. The kiddey flashes his belcher; the young fellow wears a silk handkerchief round his neck.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Belch * BellNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes