metazoan (plural metazoans)
- (zoology) Any animal that undergoes development from an embryo stage with three tissue layers, namely the ectoderm, mesoderm, and endoderm.
- (zoology) Any animal that is multicellular.
metazoan (not comparable)
- Having to do with animals that develop from an embryo with three tissue layers.
- Having to do with animals that are multicellular.