To bear a grudge against; to resent or feel bitterness toward someone or something.
過去のことをいつまでも恨んでいても仕方がない。
There's no point in holding a grudge forever over past events.
彼は裏切った友人を深く恨んでいる。
He deeply resents the friend who betrayed him.
恨まれるようなことはしたくない。
I don't want to do anything that would make someone hate me.