expression, godan verb (-su)
do someone a wrong; do an ill turn; take revenge
To harm someone or treat them unfairly, often with a nuance of returning a past wrong. Can be used for both active wrongdoing and retaliatory revenge.
彼は私に仇をなした。
He did me a wrong.
友に仇をなすようなことはするな。
Don't do an ill turn to your friend.
expression, godan verb (-su)
To hold a grudge or feel resentment, often as a result of a perceived wrong. This sense focuses on the emotional state rather than the action.
彼は長年、兄に仇をなしている。
He has borne a grudge against his older brother for years.