動詞 nail down:

1. succeed in obtaining a position
   同義詞：nail, peg
2. define clearly
   同義詞：pin down, peg down, narrow down, narrow, specify
3. make final; put the last touches on; put into final form
   同義詞：finalize, finalise, settle

1. He had a hard time selling his car, but he finally nailed down the sale when he got his friend John to give him$500.
   他原先賣不掉他的汽車，但他的朋友約翰給了他500美元，終于把這宗買賣定了下來。
2. He told us that he had lost the money but we nailed down that he had lied by proving he had spent it.
   他對我們說他丟了錢，但是我們證實(shí)是他把錢花了，從而確定他是說謊。
3. It take the negotiator ten hours to nail down a deal.
   參加協(xié)商的人花了十個小時才敲定一樁生意。