To be cruel means to deliberately cause pain or suffering to others without caring about how they feel. A cruel person might hurt someone physically, like kicking a dog or pushing a smaller kid, or emotionally, by mocking someone's failures or spreading mean rumors about them. Cruelty is different from accidents or thoughtlessness: it involves knowing that your actions will hurt someone and doing them anyway, sometimes even enjoying their pain.

You see cruelty in many forms. A cruel ruler might punish people harshly for tiny mistakes. A cruel character in a story might laugh while others suffer. Kids can be cruel too: excluding someone from a game specifically to make them feel bad, or making fun of how someone looks or talks.

The noun form is cruelty. History books document the cruelty of slavery, war, and persecution. Animal cruelty laws protect pets and wildlife from abuse.

What makes cruelty especially troubling is its coldness. Someone acting in anger might later feel sorry, but cruelty suggests a lack of basic compassion or empathy. The opposite of cruel is kind or compassionate: people who notice others' feelings and try to reduce suffering rather than add to it.