Definition from Wiktionary, the free dictionary
bruiser (plural bruisers)
- (sports) In contact sports, an athlete whose size, strength, and/or aggressiveness make it likely that he will cause athletes on the opposing team to suffer physical punishment.
- (by extension) a tall, strong, heavily built man, especially one prone to physical violence; a thug.
- His "assistant" was a big bruiser named Pete, who, with his enormous shoulders and menacing scowl, was clearly present for the intimidation factor.
- A machine for bruising oats.