own goal
noun [ C ] UK uk/ˌəʊn ˈɡəʊl/ us/ˌoʊn ˈɡoʊl/
（体育比赛中的）乌龙球，无意中帮对方得分的进球
in sport, a point that a player scores by mistake against their own team
Our team lost when we scored an own goal late in the second half. 我们队在下半场时间过半后自摆乌龙，失掉了比赛。
无意中让自己吃亏的行为
something that you do that gives you a disadvantage and helps someone else, even if this is the opposite of what you intended