"short-tempered person," 1650s, from hot in the figurative sense + head (n.); Johnson's dictionary also lists hotmouthed "headstrong, ungovernable;" Elizabethan English had hot-brain "hothead" (c. 1600); and Old English had hatheort "anger, rage," literally "hot heart."
1. He is a hothead and a bully just like his dad.
2. She's such a hothead.
3. Or some hothead trying to challenge you because his sister wants to meet you?
4. He was such a hothead, he slammed down his coffee mug and broke it.