cannon fodder vs fresh fish

cannon fodder and fresh fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
cannon fodder	Yes	No	No	No
fresh fish	Yes	No	No	No

As nouns, cannon fodder and fresh fish are synonyms defined as:

cannon fodder and fresh fish: soldiers who are regarded as expendable in the face of artillery fire

Other synonyms of cannon fodder include fodder.

cannon fodder (noun)	fresh fish (noun)
soldiers who are regarded as expendable in the face of artillery fire	soldiers who are regarded as expendable in the face of artillery fire