loosen/ˋlusṇ; ˈluːs$n/v [I,T] to become or to make something less tight or less firmly fastened(使)变松﹔松开: The screws holding the shelf had loosened. 固定搁板的螺丝松了。He loosened his tie. 他松开领带。loosen up phr v to become more relaxed 变得不拘束﹐放松: Claire loosened up after a few drinks. 几杯酒下肚后﹐克莱尔放松了下来。