greatness vs sizeableness

greatness and sizeableness both are nouns.

Word	Noun	Adjective	Verb	Adverb
greatness	Yes	No	No	No
sizeableness	Yes	No	No	No

As nouns, greatness and sizeableness are synonyms defined as:

greatness and sizeableness: unusual largeness in size or extent or number

Other synonyms of greatness include enormousness, grandness, immenseness, immensity, vastness, wideness.

greatness (noun)	sizeableness (noun)
the property possessed by something or someone of outstanding importance or eminence	unusual largeness in size or extent or number
unusual largeness in size or extent or number