coinage vs metal money

coinage and metal money both are nouns.

Word	Noun	Adjective	Verb	Adverb
coinage	Yes	No	No	No
metal money	Yes	No	No	No

As nouns, coinage and metal money are synonyms defined as:

Other synonyms of coinage include mintage, specie.

coinage (noun)	metal money (noun)
the act of inventing a word or phrase	coins collectively
a newly invented word or phrase
coins collectively