"unanticipated and disconcerting lines of development"
"unforeseen circumstances"
"a virtue unlooked-for in people so full of energy"
"like a bolt out of the blue"
例句
用作形容词 (adj.)
You were responsible for that accident. 你应对那意外的事故负责。
The unexpected answer threw the lecturer out for a moment. 意外的回答使演讲者愣一会儿。