IPA: /ɪmˌpæsəˈbɪlɪti/
KK: /ɪmˌpæsəˈbɪlɪti/
The state of being unable to be affected by emotions or feelings; showing no response to external influences.
Her impassibility during the crisis surprised everyone around her.
Impassibility is formed from "im-" (meaning not) and "passibilis" (from Latin, meaning able to suffer or feel). The word describes a state of being not able to suffer or feel, often used in philosophical or theological contexts to refer to an entity that is unaffected by external circumstances.
Think of 'not' ('im-') being able to 'suffer' ('passibilis') — that's why impassibility means a state of being unable to feel or suffer.