The plea of pregnancy, generally adduced by female felons capitally convicted, which they take care to provide for, previous to their trials; every gaol having, as the Beggar’s Opera informs us, one or more child getters, who qualify the ladies for that expedient to procure a respite.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Belly Cheat * Belly TimberNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes