Straighten (verb)

1. To make or become straight.
2. To put in order; to make neat and tidy.
3. To correct or put right.
4. To resolve or clarify.

Origin:

Early 16th century (in the sense "make straight"): from straight + -en.

Examples:

1. She straightened the picture on the wall.
2. He straightened his tie before the interview.
3. She straightened out the problem with the customer.
4. He straightened his hair with a flat iron.
5. The company straightened out the financial problems with the help of a new accountant.