invention vs coinage

invention and coinage both are nouns.

Word	Noun	Adjective	Verb	Adverb
invention	Yes	No	No	No
coinage	Yes	No	No	No

As nouns, coinage is a hyponym of invention; that is, coinage is a word with a more specific, narrower meaning than invention:

Other hyponyms of invention include neologism, neology, contrivance, devisal.

invention (noun)	coinage (noun)
the act of inventing	the act of inventing a word or phrase
a creation (a new device or process) resulting from study and experimentation	a newly invented word or phrase
the creation of something in the mind	coins collectively