nail down

verb

1. to fasten down with or as if with nails
2. informal.
   to extort a definite promise or consent from

   I nailed him down on the deadline

3. informal.
   to settle in a definite way

   they nailed down the agreement

Idioms and Phrases

Establish conclusively, as in The reporter nailed down the story by checking all the facts . This metaphoric expression alludes to fixing or fastening something down with nails. [c. 1600]

Example Sentences

Not enough that Democrats can win Arkansas, God knows, but maybe enough that they can nail down North Carolina again.

From The Daily Beast

August isn't really the time to be trying to nail down the scary-lazy-black-people and the Democrats-hate-God voting blocs.

From The Daily Beast

Actually, hard numbers on the safety of home birth are surprisingly difficult to nail down.

From The Daily Beast

Romney, for his part, still cannot win blue-collar votes and still cannot nail down evangelical support.

From The Daily Beast

We were trying to nail down the schedule for it to air, with the goal of it being Thursday night.

From The Daily Beast

I recovered just as the people were about to nail down the hatches; perceiving which, I desired them to stop.

From Project Gutenberg

In other words, I was trying to nail down where this lie started.

From Project Gutenberg

We shall nail down the transom and stuff the keyhole with soap if you do.

From Project Gutenberg

Ryan at once took out the saw, poured some oil on it, and passed his nail down the bar until he found a fine nick.

From Project Gutenberg

Nail down the rear end upon floor to its widest spread, with hind legs pointing back on a slight slant.

From Project Gutenberg