massive vs massiveness

massive is not a noun while massiveness is a noun.

Word	Noun	Adjective	Verb	Adverb
massive	No	Yes	No	No
massiveness	Yes	No	No	No

massive (noun)	massiveness (noun)
	an unwieldy largeness
	the property of being large in mass

massive (adjective)	massiveness (adjective)
consisting of great mass; containing a great quantity of matter
imposing in size or bulk or solidity
being the same substance throughout
imposing in scale or scope or degree or power