E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
or Abraham Cove. A Tom o Bedlam; a naked vagabond; a begging impostor.
The Abraham Ward, in Bedlam, had for its inmates begging lunatics, who used to array themselves with party-coloured ribbons, tape in their hats, a fox-tail hanging down, a long stick with streamers, and beg alms; but for all their seeming madness, they had wit enough to steal as they went along.Canting Academy.
See King Lear, ii. 3.
In Beaumont and Fletcher we have several synonyms: