foursome/fɔ:r.sʌm/复数形式foursomes1四, 四人组the cardinal number that is the sum of three and one同义词: IVLittle Joequartetquadrupletquaternityquaternionquaternquaternarytetradfour2四人组, 由四个成员组成的团体a group consisting of four members同义词: quartetquartette