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.
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.
sadness associated with some wrong done or some disappointment; "he drank to drown his sorrows"; "he wrote a note expressing his regret"; "to his rue, the error cost him the game"
feel remorse for; feel sorry for; be contrite about
feel sad about the loss or absence of
be sorry; "I regret to say that you did not gain admission to Harvard"
Regret is an intelligent (and/or emotional) dislike for personal past acts and behaviors. Regret is often felt when someone feels sadness, shame, or guilt after committing an action that the person later wishes that he or she had not done. Regret is distinct from guilt, which is a deeply emotional form of regret — one which may be difficult to comprehend in an objective or conceptual way.