IPA: //ʌnˈflæpəˌbɪlɪti//
KK: /ʌnˈflæpəˌbɪlɪti/
The quality of remaining calm and composed, especially in difficult or stressful situations.
Her unflappability during the crisis impressed everyone around her.
Unflappability → It is formed from the prefix "un-" (meaning not), the root "flap" (from Old English *flæppan*, meaning to move or wave), and the suffix "-ability" (meaning the quality of being able to). The word describes the quality of not being easily disturbed or agitated, as if one does not flap or wave in response to stress.
Think of someone who is 'not' ('un-') easily 'moved' ('flap') by stress, showing that they have the quality of remaining calm.