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resentment; grudge; malice; bitterness
matter for regret; regret
彼は長年の怨みを胸に秘めていた。
He kept years of resentment hidden in his heart.
怨みを買うような行動は避けるべきだ。
You should avoid behavior that invites resentment.
怨みを晴らしても何も解決しない。
Even avenging a grudge does not solve anything.