metamorphosis ˌmɛtəˈmɔːfəsɪs,ˌmɛtəmɔːˈfəʊsɪs/ noun ZOOLOGY (in an insect or amphibian) the process of transformation from an immature form to an adult form in two or more distinct stages. "the persistence of the larval tail during metamorphosis" a change of the form or nature of a thing or person into a completely different one. "his metamorphosis from presidential candidate to talk-show host" None of the above.