innovative vs groundbreaking

innovative is not a noun while groundbreaking is a noun.

Word	Noun	Adjective	Verb	Adverb
innovative	No	Yes	No	No
groundbreaking	Yes	Yes	No	No

As adjectives, innovative and groundbreaking are synonyms defined as:

innovative and groundbreaking: being or producing something like nothing done or experienced or created before

Other synonyms of innovative include innovational.

innovative (noun)	groundbreaking (noun)
	the ceremonial breaking of the ground to formally begin a construction project

innovative (adjective)	groundbreaking (adjective)
being or producing something like nothing done or experienced or created before	being or producing something like nothing done or experienced or created before
ahead of the times