B1 noun, verb /ˈbʊli/
bully
いじめっ子 / 加害者
Meaning
A person who habitually seeks to harm or intimidate those weaker; to intimidate or mistreat someone weaker.
Example
The teacher stopped the older boy from trying to bully his classmates.
先生は年上の男の子がクラスメートをいじめるのを止めました。