v.1. To make something conform to a desired plane, straight line, or right angle: He squared up the picture and nailed it in place. The golfer squared her feet up to the hole.
2. To make one's body, especially one's feet or shoulders, conform to a desired plane, straight line, or right angle: The football players squared up to the line of scrimmage. The basketball player squared up and shot a free throw.
3. square up to To come face to face with someone or something, especially with defiance or hostility; confront someone or something: The prisoners squared up to the guards and demanded better food.
4. To face one another in a competition: The two teams will square up tonight.
5. To settle some bill or debt: We went to the bar to square up our bill from the night before. The landlord demanded that I square up before the end of the month.