The Collaborative International Dictionary of English v.0.48:

Abraham-man \A"bra*ham-man`\or Abram-man \A"bram-man`\, n.
   [Possibly in allusion to the parable of the beggar Lazarus in
   Luke xvi. --Murray (New Eng. Dict. ).]
   One of a set of vagabonds who formerly roamed through
   England, feigning lunacy for the sake of obtaining alms.
   --Nares.
   [1913 Webster]

   To sham Abraham, to feign sickness. --Goldsmith.
      [1913 Webster]