expression, godan verb (-su)
avenge oneself; get revenge; settle a grudge
Used when someone takes action to satisfy a long-held resentment or grudge, often implying a personal, emotional motivation rather than formal justice.
彼は長年の恨みを晴らすために復讐を計画した。
He planned revenge to avenge his long-held grudge.
By winning the match, they avenged their previous loss.