Insensibility is a synonym of impassiveness.
As nouns the difference between insensibility and impassiveness
is that insensibility is the property of being insensible while impassiveness is the state of being impassive.
insensibility
English
Noun
(insensibilities)
The property of being insensible.
impassiveness
English
Noun
(-)
The state of being impassive.
Synonyms
* impassivity