1 [U] the act of showing that you have seen or noticed sb/sth 答理；确认: The president gave a smile of acknowledgement to the photographers. 总统微微一笑，跟摄影师们打招呼。

2 [C,U] a letter, etc that says that sth has been received or noticed （表示已收到或注意到某物的）回信，回音: I haven't received (an) acknowledgement of my job application yet. 我还没有收到申请工作的回音。

3 [C] [usu.pl] a few words of thanks that an author writes at the beginning or end of a book to the people who have helped him/her （书的作者写于正文前或后向出过力的人表示谢意的）鸣谢，志谢