straighten up

verb7

1. •
   To become straight, or straighter.

   • bank the big cruiser into the first of a series of corners, make a few quick left, right, left transitions, then the road straightens up for a stretch... — 2006
2. •
   To steer straight.

   • 13 October 2010, Blackpool Gazette, 'Bad driving' led to biker death crash He said "As I came out of the bend I went to straighten up the car and it just seemed to be carrying on turning."
3. •
   To sit up straight, to stop hunching.

   • Horse skin smells good. Lay your cheek against his neck and have a good cuddle. Now straighten up slowly again, and sit loosely. — 2005
4. •
   To deal with; to put in order.

   • The Postal Service sent a special task force to straighten up the city's problems with a back-to-basics approach — 1994
5. •
   To tidy; to tidy up.
6. •
   To start living a reformed life; to adopt a more honest and respectable course of behavior.
7. •
   To clarify.