N-COUNT [usually singular](委员会主席在赞成票和反对票相等时所投的)决定性票，关键票 When a committee has given an equal number of votes for and against a proposal, the chairperson can give a casting vote. This vote decides whether or not the proposal will be passed. (委员会主席在赞成票和反对票相等时所投的)决定性票，关键票
The vote was tied and a local union leader used his casting vote in favour of the return to work.