1 to cause sb to feel such a strong emotion that he/she does not know how to react 使受强烈感情冲击，以致不知所措: The new world champion was overwhelmed by all the publicity. 新的世界冠军因受到大众注目而感到不知所措。

2 to be so powerful, big, etc, that sb cannot deal with it （因强大、巨大等而）无力应付: He overwhelmed his opponent with his superb technique. 他以高超的技术击败了对手。The television company were overwhelmed by complaints. 电视公司接到无数投诉，简直应接不暇。