Pronunciation Audio (US)(file) Adjective Positive amphibious Comparative none Superlative none If an animal is amphibious it lives in water when it is young and lives on land when it is an adult. Frogs are amphibious. If something is amphibious it happens or can function on land and in water. The DUKW is an amphibious vehicle that was used during World War II.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads