1 a short piece of wood, plastic, etc that is put through a loop of thread to fasten sth, such as a coat or bag, instead of a button ﹙大衣或口袋等上木质或塑料的﹚栓扣钉，棒形钮扣

2 (also toggle switch) (computing 计算机技术) a key on a computer that you press to change from one style or operation to another, and back again ﹙计算机上的﹚切换键；转换键