The Collaborative International Dictionary of English v.0.48:

mangy \man"gy\, a. [Compar. mangier; superl. mangiest.] [F.
   mang['e], p. p. of manger to eat. See Manger.]
   1. Infected with the mange; scabby.
      [1913 Webster]

   2. Shabby; worn-out; seedy; run-down; squalid; as, a mangy
      old coat; a mangy tavern.
      [PJC]