Sponge (6)
'sponge' is the definition.
(synonyms)
This is all the clue.
(Other definitions for cadge that I've seen before include "Try to borrow" , "Scrounge, sponge" , "Sponge (money, etc)" , "get free" , "freeload" .)
(Other definitions for sponge that I've seen before include "Cadge - porous object used for washing" , "something to eat" , "Porous substance found in the ocean" , "Marine animal often found in bathroom" , "No pegs on this substance to soak up" .)