expansivity vs effusiveness

expansivity and effusiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
expansivity	Yes	No	No	No
effusiveness	Yes	No	No	No

As nouns, expansivity and effusiveness are synonyms defined as:

expansivity and effusiveness: a friendly open trait of a talkative person

Other synonyms of expansivity include expansiveness.

expansivity (noun)	effusiveness (noun)
a friendly open trait of a talkative person	a friendly open trait of a talkative person
a quality characterized by magnificence of scale or the tendency to expand
the fractional change in length or area or volume per unit change in temperature at a given constant pressure