Definitions
1.NounIn contact sports, an athlete whose size, strength, and/or aggressiveness make it likely that they will cause athletes on the opposing team to suffer physical punishment.
2.NounA tall, strong, heavily built person, usually a man, especially one prone to physical violence; a strong and tough person."His "assistant" was a big bruiser named Pete, who, with his enormous shoulders and menacing scowl, was clearly present for the intimidation factor."
3.NounA machine for bruising oats.
4.NounA person who enjoys arguing with others.
5.NounA professional boxer.