A primitive sedentary aquatic invertebrate with a soft porous body that is typically supported by a framework of fibers or calcareous or glassy spicules. Sponges draw in a current of water to extract nutrients and oxygen. A piece of a soft, light, porous substance originally consisting of the fibrous skeleton of an invertebrate but now usually made of synthetic material. Sponges absorb liquid and are used for washing and cleaning. A person who lives at someone else's expense. Wipe, rub, or clean with a wet sponge or cloth. Obtain or accept money or food from other people without doing or intending to do anything in return.