Make sure the post is 'square' to the floor. [=make sure that there is a right angle where the post and the floor meet]
I'll go on the trip if I can 'square it with' my parents. [=if my parents will agree to let me go]
Here's the rest of the money. Now we're 'square'. [=now we don't owe each other anything]
(..) Kramer, do me a favour, will you? If you insist on making pasta in my apartment... ...please don't put the tomato sauce on the pasta while it's in the strainer. All the little squares have hardened red sauce in them. What's so funny? Oh, I don't know. Kramer dating your roommate, it's funny. (..)1991 TvShow: Seinfeld Title: The Truth Season: 3 Episode 2