pontoon vs amphibian

pontoon and amphibian both are nouns.

Word	Noun	Adjective	Verb	Adverb
pontoon	Yes	No	No	No
amphibian	Yes	Yes	No	No

pontoon (noun)	amphibian (noun)
a float supporting a seaplane	cold-blooded vertebrate typically living on land but breeding in water; aquatic larvae undergo metamorphosis into adult form
(nautical) a floating structure (as a flat-bottomed boat) that serves as a dock or to support a bridge	an airplane designed to take off and land on water
	a flat-bottomed motor vehicle that can travel on land or water

pontoon (adjective)	amphibian (adjective)
	relating to or characteristic of animals of the class Amphibia