#1 sponge v. wipe with a sponge, so as to clean or moisten. wn
#2 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. wn
#3 sponge n. [quick study] someone able to acquire new knowledge and skills rapidly and easily; "she soaks up foreign languages like a sponge". wn
#4 sponge v. [mooch, bum, cadge, grub] ask for and get free; be a parasite. wn
#5 sponge n. [leech, parasite, sponger] a follower who hangs around a host (without benefit to the host) in hope of gain or advantage. wn
vizzz