Source : Webster's Revised Unabridged Dictionary (1913)

Sponger \Spon"ger\, n.
   1. One who sponges, or uses a sponge.

   2. One employed in gathering sponges.

   3. Fig.: A parasitical dependent; a hanger-on.

Source : WordNet®

sponger
     n 1: a workman employed to collect sponges
     2: a follower who hangs around a host (without benefit to the
        host) in hope of gain or advantage [syn: {leech}, {parasite},
         {sponge}]