unsure

形容词 unsure:

1. lacking or indicating lack of confidence or assurance
   同义词：uncertain, incertain
2. lacking self-confidence
   同义词：diffident, shy, timid

1. Beneath her self-confident surface, she's quite unsure of herself.
   她看上去信心十足，实际上很缺乏信心。
2. As if unsure of where she was, she hesitated and looked round.
   她彷佛茫然不知身在何处，犹犹豫豫向四周打量。