ETYM Latin polypus, Greek, literally, many-footed; polys many + pod foot: cf. French polype. Related to Poly- and Foot, Polypode, Polypody, Poulp.
In zoology, the sedentary stage in the life cycle of a coelenterate (such as a coral or jellyfish), the other being the free-swimming medusa.
One of two forms that coelenterates take e.g. a hydra or coral: usually sedentary and has a hollow cylindrical body usually with a ring of tentacles around the mouth.
Hollow-bodied, tentacled marine invertebrate, as coral, sea-anemone, etc. small growth on mucous membrane.

Or polypus; Small “stalked” benign tumor, usually found on mucous membrane of the nose or bowels. Intestinal polyps are usually removed, since some have been found to be precursors of cancer.A small vascular growth on the surface of a mucous membrane; SYN. polypus.