nail down

基本解释

A few exercises helped me nail down my ultimate satisfaction-generating personal business model.
一些练习帮助我最终敲定了这个为了创造满足感的个人商业模式。
Starting with the frame list keeps the storyboard organized and helps you nail down the step-by-step outline before delving into the details of each frame or sketch.
以框架列表开始可以使故事板有组织，而且还可以帮助你钻研每一框架或者示意图细节之前确定一步步的纲要。
Moreover, new services have emergedthat will help you—for a sometimes-substantial fee—nail down the username ofyour choice, assuming it isn’t already taken, at dozens or even hundreds ofsites.
另一方面，十几个甚至上百个网站都推出了新的服务，旨在帮用户绑定他们所选择的，假定还未被注册的用户名，同时收取一定的费用。

The 2007 World Series between the Boston Red Sox and Colorado Rockies should lay to rest one of the great myths of modern baseball: that a dominant "closer"--a high-priced pitching ace who enters a game in the final inning to nail down a victory--is a must-have for success.
FORBES: Magazine Article
By that I mean first nail down the core 4-5 keywords you know are critical and then branch out for more related terms or phrases.
FORBES: Do You Know Your 10 Most Important Keywords?
Most will work with you--and you want to nail this down before you burn through your savings.
FORBES: Deciphering A Credit Report

If you nail down something unknown or uncertain, you find out exactly what it is.
If you nail down an agreement, you manage to reach a firm agreement with a definite result.