Synonyms for Amphibian (same or very similar meaning)
WordNet sense 1 (relating to or characteristic of animals of the class Amphibia):
amphibious
WordNet sense 2 (a flat-bottomed motor vehicle that can travel on land or water):
amphibious vehicle
WordNet sense 3 (an airplane designed to take off and land on water):
amphibious aircraft
From the ODE community, based on WordNet
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