N-SING 副指挥;二把手 A second-in-command is someone who is next in rank to the leader of a group, and who has authority to give orders when the leader is not there. 副指挥;二把手
He was posted to Hong Kong as second-in-command of C Squadron.
他被派遣到香港任C中队的副队长。
The President was replaced by his second-in-command.