nailsthdown
—phrasal verbwithnailverbuk/neɪl/us/neɪl/
(DECISION)
informal
If younaildown anarrangementordecision, youdecideandagreeto thedetailsof it.
敲定（协议）；最终确定（或决定）
After a five-hourmeeting, wefinallynaileddown adeal.开了5个小时的会后，我们最终达成了一项协议。
(UNDERSTAND)
USinformal
tounderstandsomethingcompletely, or todescribesomethingcorrectly
完全理解；正确描述
We haven't beenabletonaildown thecauseof thefireyet.我们仍未弄清火灾的起因。