largeness vs extensiveness

largeness and extensiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
largeness	Yes	No	No	No
extensiveness	Yes	No	No	No

As nouns, largeness and extensiveness are synonyms defined as:

largeness and extensiveness: large or extensive in breadth or importance or comprehensiveness

largeness (noun)	extensiveness (noun)
the property of having a relatively great size	large or extensive in breadth or importance or comprehensiveness
large or extensive in breadth or importance or comprehensiveness
the quality of being pretentious (behaving or speaking in such a manner as to create a false appearance of great importance or worth)
the capacity to understand a broad range of topics