concentrated fire vs massed fire

concentrated fire and massed fire both are nouns.

Word	Noun	Adjective	Verb	Adverb
concentrated fire	Yes	No	No	No
massed fire	Yes	No	No	No

As nouns, concentrated fire and massed fire are synonyms defined as:

concentrated fire and massed fire: fire from two or more weapons directed at a single target or area (as fire by batteries of two or more warships)

concentrated fire (noun)	massed fire (noun)
fire from two or more weapons directed at a single target or area (as fire by batteries of two or more warships)	fire from two or more weapons directed at a single target or area (as fire by batteries of two or more warships)