menage a trois/ˌmeɪnɑ:ʒ ɑ: ˈtrwɑ:; menɑʒ ɑ `trwɑ/ (French 法) household consisting of a husband, a wife and the lover of one of them 三角家庭（夫妇与其一之情人三人同居）.
牛津英汉双解词典