brutish
Cruel and rough, acting like a violent, thoughtless animal.
Brutish means behaving in a crude, violent, or animal-like way, without thought or kindness. Someone acting brutish treats others roughly and carelessly, like a bully who shoves smaller kids aside in the hallway or steals their lunch money. The word suggests behavior that's more like a mindless beast than a thinking person.
In literature, you might read about a brutish guard who controls prisoners through fear and force rather than fairness. A brutish ruler governs through threats and violence instead of wisdom and justice. The word often appears when describing people who rely on physical strength or aggression instead of intelligence or compassion.
When we call behavior brutish, we're saying it lacks the qualities that make us human: reasoning, empathy, and self-control. A chess player uses strategy and thought; a brutish opponent just tries to intimidate you into making mistakes.