pontoon bridge vs floating bridge

pontoon bridge and floating bridge both are nouns.

Word	Noun	Adjective	Verb	Adverb
pontoon bridge	Yes	No	No	No
floating bridge	Yes	No	No	No

As nouns, pontoon bridge and floating bridge are synonyms defined as:

pontoon bridge and floating bridge: a temporary bridge built over a series of pontoons

Other synonyms of pontoon bridge include bateau bridge.

pontoon bridge (noun)	floating bridge (noun)
a temporary bridge built over a series of pontoons	a temporary bridge built over a series of pontoons