gazump
verb [ T often passive ] UK informal uk/ɡəˈzʌmp/ us/ɡəˈzʌmp/
（房价议定后因有人出价更高而向买主）食言毁约
to refuse to sell a house that you own to someone you have agreed to sell it to, and to sell it instead to someone who offers to pay more for it
Sally's offer for the house has been accepted, but she's worried she might be gazumped. 萨莉出的房价卖主接受了，但是她担心若有更高的出价卖主会食言毁约。