im·per·turb·able 
/ˌɪmpɚˈtɚbəbəl/ adjective
/ˌɪmpɚˈtɚbəbəl/ adjective [more imperturbable; most imperturbable] formal : very calm : very hard to disturb or upset
▪ Although he seems outwardly imperturbable, he can get very angry at times. ▪ an imperturbable demeanor/disposition
▪ Although he seems outwardly imperturbable, he can get very angry at times. ▪ an imperturbable demeanor/disposition
— im·per·turb·abil·i·ty /ˌɪmpɚˌtɚbəˈbɪləti/ noun [noncount]
/ˌɪmpɚˌtɚbəˈbɪləti/ noun [noncount]— im·per·turb·ably /ˌɪmpɚˈtɚbəbli/ adverb
▪ He sat there imperturbably as they insulted him.
/ˌɪmpɚˈtɚbəbli/ adverb ▪ He sat there imperturbably as they insulted him.
