imagination vs inventiveness

imagination and inventiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
imagination	Yes	No	No	No
inventiveness	Yes	No	No	No

As nouns, inventiveness is a hypernym of imagination; that is, inventiveness is a word with a broader meaning than imagination:

Other hypernyms of imagination include cleverness, ingeniousness, ingenuity.

imagination (noun)	inventiveness (noun)
the formation of a mental image of something that is not perceived as real and is not present to the senses	the power of creative imagination
the ability to form mental images of things or events
the ability to deal resourcefully with unusual problems