marine museum vs fish tank

marine museum and fish tank both are nouns.

Word	Noun	Adjective	Verb	Adverb
marine museum	Yes	No	No	No
fish tank	Yes	No	No	No

As nouns, marine museum and fish tank are synonyms defined as:

marine museum and fish tank: a tank or pool or bowl filled with water for keeping live fish and underwater animals

Other synonyms of marine museum include aquarium.

marine museum (noun)	fish tank (noun)
a tank or pool or bowl filled with water for keeping live fish and underwater animals	a tank or pool or bowl filled with water for keeping live fish and underwater animals