polyp vs polypus

polyp and polypus both are nouns.

Word	Noun	Adjective	Verb	Adverb
polyp	Yes	No	No	No
polypus	Yes	No	No	No

As nouns, polyp and polypus are synonyms defined as:

polyp and polypus: a small vascular growth on the surface of a mucous membrane

polyp (noun)	polypus (noun)
one of two forms that coelenterates take (e.g. a hydra or coral): usually sedentary with a hollow cylindrical body usually with a ring of tentacles around the mouth	a small vascular growth on the surface of a mucous membrane
a small vascular growth on the surface of a mucous membrane