1. Of weather, to become clear or fair. There are going to be thunderstorms in the morning, but it should fair up by midday.
2. To make something smooth, flush, or even, especially when joining two or more different parts together. We'll use some mortar to fair up the tiles once they're in place. Today we'll be learning how to fair up the seams on the hull of the boat we're building.
3. To get along; to fare in some way. Usually used in a comparison between two different situations or environments. ("Fair" in this usage is a misspelling of "fare.") I hope he fairs up better in this new job than he did in his last one. The judge agreed that the defendant would fair up better in rehab than in prison.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.