sponge in WordNet English dictionary

1. ask for and get free; be a parasite
   mooch  bum  cadge  grub  sponge 
   
2. wipe with a sponge, so as to clean or moisten
   sponge 
   
3. erase with a sponge; as of words on a blackboard
   sponge 
   
4. soak up with a sponge
   sponge 
   
5. gather sponges, in the ocean
   sponge 
   

1. a follower who hangs around a host (without benefit to the host) in hope of gain or advantage
   leech  parasite  sponge  sponger 
   
2. primitive multicellular marine animal whose porous body is supported by a fibrous skeletal framework; usually occurs in sessile colonies
   sponge  poriferan  parazoan 
   
3. someone able to acquire new knowledge and skills rapidly and easily
   "she soaks up foreign languages like a sponge"
   quick study  sponge 
   
4. a porous mass of interlacing fibers that forms the internal skeleton of various marine animals and usable to absorb water or any porous rubber or cellulose product similarly used
   sponge