unkind
Not nice and hurting others’ feelings on purpose.
Unkind means treating others in a way that hurts their feelings or shows a lack of care and consideration. When someone is unkind, they might say mean things, exclude others on purpose, or ignore someone who needs help.
Being unkind is different from accidentally hurting someone's feelings. If you step on someone's toe by mistake, that's not unkind. But if you see someone sitting alone at lunch and deliberately make fun of them, or if you know your words will hurt and say them anyway, that's unkind.
Unkind behavior can be obvious, like calling someone names or laughing at their mistakes. But it can also be quieter, like purposely leaving someone out of a game or ignoring them when they're trying to talk to you. Sometimes people act unkind because they're having a bad day themselves, though that doesn't excuse the behavior.
The opposite of unkind is kind or considerate. When you notice that your actions or words might hurt someone and you choose a gentler path instead, you're being kind rather than unkind.