will kill all the birds that died last summer. A piece of wit commonly thrown out at a person walking through a street or village near London, with a gun in his hand.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Peter * Peter LayNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes