. To cause to grieve; make repentant, compassionate, or sorrowful; afflict: often used impersonally with a personal pronoun.To repent of; feel remorse for; regret; hence, to suffer in expiation of: as, to rue one's folly or mistakes.To feel sorrow or suffering on account of; suffer from or by; experience loss or injury from.To have or take pity on; feel sorry for; compassionate.To repent of and withdraw, or try to withdraw, from: as, to rue a bargain. See rue-bargain.To be sorrowful; experience grief or harm; suffer; mourn.To repent; feel remorse or regret.To have pity; have compassion or mercy: often followed by on or upon.n. Sorrow; repentance.n. Any plant of the genus Ruta, especially R. graveolens, the common or garden rue, a native of the Mediterranean region and western Asia, and elsewhere common in cultivation.