demoiselle vs damselfish

demoiselle and damselfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
demoiselle	Yes	No	No	No
damselfish	Yes	No	No	No

As nouns, demoiselle and damselfish are synonyms defined as:

demoiselle and damselfish: small brilliantly colored tropical marine fishes of coral reefs

demoiselle (noun)	damselfish (noun)
small brilliantly colored tropical marine fishes of coral reefs	small brilliantly colored tropical marine fishes of coral reefs
a young unmarried woman