neck down(redirected from necks down)
1. To drink something very quickly, especially in a single gulp. A noun or pronoun can be used between "neck" and "down." The bartender did his last call, so we necked down our drinks and ordered one last round. I hate having to neck my coffee down like that!
2. To alter the diameter of a case in order to hold a smaller caliber bullet. The .308 Winchester can be necked down to accept a variety of different bullets, depending on what you plan to hunt.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.