transfer window
noun [ C usually singular ] UK uk/ˈtræns.fɜː ˌwɪn.dəʊ/ us/ˈtræns.fɝː ˌwɪn.doʊ/
（足球赛季中允许俱乐部买卖队员的一段时间）转会窗口
a short period within the football season during which clubs can buy and sell players
He will probably be leaving the club when the transfer window opens in January. 他可能会在一月份转会窗口期间离开俱乐部。