Bidding at an auction, as above; also praising any thing above its merits, from interested motives. The art of puffing is at present greatly practised, and essentially necessary in all trades, professions, and callings. To puff and blow; to be out of breath.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Puff Guts * PugNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes