sponge

n. 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 n. primitive multicellular marine animal whose porous body is supported by a fibrous skeletal framework; usually occurs in sessile colonies v. wipe with a sponge, so as to clean or moisten v. erase with a sponge; as of words on a blackboard