[, ]the vote given by the person in charge of an official meeting to decide an issue when there are an equal number of votes on each side （赞成票数和反对票数相等时会议主席所投的）决定票◆The chairman has the casting vote. 主席掌握决定性的一票。⨁to give / have / use a casting vote 投／有／行使决定性的一票