grit one's teeth

1. Summon up one's strength to face unpleasantness or overcome a difficulty. For example, Gritting his teeth, he dove into the icy water. This expression uses grit in the sense of both clamping one's teeth together and grinding them with effort. [Late 1700s]

Example Sentences

Instead one may opt to grit one's teeth and bear the discomfort—for example, if a reward is at stake.

From Scientific American

Those are the times to remember these horrible, frustrating images and use the emotions to grit one's teeth and get up and go once again.

From Newsweek

There was nothing to do but grit one's teeth and take chances.

From Project Gutenberg