Green’s Dictionary of Slang

abram-man n.

also abram-cove, abram-mort
[var. on abraham-man n. + cove n. (1)/mort n.]

1. [17C–19C] a wandering beggar, adopting tattered clothing and posing as a mad person.

2. [late 17C–mid-19C] a ‘sturdy beggar’, i.e. one who could, but rarely does, work for a living.

3. [late 18C–mid-19C] a thief specializing in pocket-books.