To sleep like a cow, with a **** at one’s a-se; said of a married man; married men being supposed to sleep with their backs towards their wives, according to the following proclamation:
All you that in your beds do lie,
Turn to your wives, and occupy:
And when that you have done your best,
Turn a-se to a-se, and take your rest.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Court of Assistants * Cow JuiceNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes