1. mod. old-fashioned; law-abiding; stodgy. Man, you are really square.
2. n. a person who behaves properly. You are a square if I ever saw one.
3. and square joint n. a tobacco cigarette, compared to a marijuana cigarette. I’ll take a reefer. I’ve heard that square joints will give you cancer.
4. tv. to settle or to make something right. Will twenty bucks square the matter?
5. Go to square (meal).