/pɪn ||; pɪn/verb [T] (
pinning;pinned)
1 pin sth to/on sth;pin sth together to fasten sth with a pin or pins 用针别住；用夹子固定: Could you pin this notice on the board, please? 请你把这张通知钉在布告板上，可以吗？
2 pin sb/sth against, to, under, etc sth to make sb/sth unable to move by holding or pressing down on him/her/it 使不能动弹；按住；压住: He caught his brother and pinned him to the floor. 他捉住他的弟弟，把他按在地板上。He was pinned under the fallen tree. 他被那棵倒下来的树压住了。
pin (all) your hopes on sb/sth to believe completely that sb/sth will help you or will succeed 把希望全部寄托在…之上
pin sb down 1 to hold sb so he/she cannot move 使某人不能移动；按住某人
2 to force sb to decide sth or to say exactly what he/she is going to do 迫使某人决定某事；使确切地说明意图: Can you pin her down to what time she'll be coming? 你能叫她定下来访的时间吗？
pin sth down to describe or explain exactly what sth is 确切地描述或解释某事物