留活口

留活口

Literally means:

spare the life of someone who can give clues or information; leave room for maneuver

Actually means:

活口 refers to an informant, i.e. someone who can give clues or information. It means survivor or an informant of murder attempt.

It also refers to a criminal or prisoner whose life is spared intentionally in the arresting and killing action so as to obtain clues for the case. Often used in the negative form in this case.

It metaphorically means that one does not say absolute words, leaving room for discussion or concession. It also refers to leaving a loophole that others can take advantage of in a contract or its clauses, or intentionally keep them flexible.

活口，可以提供线索或者情况的人。留活口，指凶杀案件中未被杀害的幸存者或知情人。也指在捕杀行动中，被有意留下活命的犯罪分子，以便获取案件的线索。在第一种情况中，多用否定形式。

比喻话没有说死，还有商量的余地。也指合约或条款中留下可以被人利用的空子，或有意保留灵活变通的余地。