(1):
(n.) An organic body or cell having locomotion, as a spermatic cell or spermatozooid.
(2):
(n.) An animal in one of its inferior stages of development, as one of the intermediate forms in alternate generation.
(3):
(n.) One of the individual animals in a composite group, as of Anthozoa, Hydroidea, and Bryozoa; - sometimes restricted to those individuals in which the mouth and digestive organs are not developed.
(4):
(a.) Pertaining to, or resembling, an animal.