The Collaborative International Dictionary of English v.0.48:

Hanger-on \Hang"er-on`\ (-[o^]n`), n.; pl. Hangers-on
   (-[~e]rz-[o^]n`).
   One who hangs on, or sticks to, a person, place, or service;
   a dependent; one who adheres to others' society longer than
   he is wanted. --Goldsmith.
   [1913 Webster]