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to ill-treat; to bully; to torment; to pick on; to tease; to be cruel to; to persecute
to be tough on (e.g. one's body); to treat harshly
私は誰のこともいじめたりしません。
I don't do things like bully.
年上の子が小さい子をいじめて泣かせた。
The older child bullied the younger one and made them cry.
上級生が下級生をいじめている。
The upperclassmen are bullying the underclassmen.