stolidity vs impassivity

stolidity and impassivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
stolidity	Yes	No	No	No
impassivity	Yes	No	No	No

As nouns, stolidity and impassivity are synonyms defined as:

stolidity and impassivity: apathy demonstrated by an absence of emotional reactions

Other synonyms of stolidity include emotionlessness, impassiveness, indifference, phlegm, unemotionality.

stolidity (noun)	impassivity (noun)
an indifference to pleasure or pain	apathy demonstrated by an absence of emotional reactions
apathy demonstrated by an absence of emotional reactions