Regret(v.) Pain of mind on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing; grief; sorrow; especially, a mourning on account of the loss of some joy, advantage, or satisfaction.
Regret(v.) Dislike; aversion.
Regret(v. t.) To experience regret on account of; to lose or miss with a sense of regret; to feel sorrow or dissatisfaction on account of (the happening or the loss of something); as, to regret an error; to regret lost opportunities or friends.
Regretful(a.) Full of regret; indulging in regrets; repining.
Regretted(imp. & p. p.) of Regret
Regretting(p. pr. & vb. n.) of Regret

Words within regrets