[with obj.]disturb the composure of; unsettle 使惊慌失措;使不安 the abrupt change of subject disconcerted her. 突然变换主题让她措手不及。 [as adj. disconcerted]she was amused to see a disconcerted expression on his face. 她饶有兴趣地看着他脸上惊慌的表情。
late 17th cent. (in the sense 'upset the progress of'): from obsolete French desconcerter, from des- (expressing reversal) + concerter 'bring together'