fasten down
1．fix firmly in place扎牢
You will have to fasten the lid down with nails．你必须用钉子把盖子钉牢。
The windows have been fastened down．窗户都已扣牢了。
He fastened down the collar of his coat．他扣紧了大衣领子。
2. make sb．give a decision使（某人）下决心
Can you fasten him down to a date？你能使他确定一个日期吗？