adj.沉着的；泰然自若的；镇静的

Hitherto imperturbable, he now showed signs of alarm. 到现在为止都很沉着，但现在他表现出了惊慌的迹象。

The Doctor's indignation was wholly lost on his imperturbable rival. 医生的愤慨对于他的泰然自若的敌手也是毫无作用。

She was one of those imperturbable people who never get angry or upset. 她是那种从不生气也不烦恼的人。