regret

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

decline formally or politely; "I regret I can't come to the party"

express with regret; "I regret to say that you did not gain admission to Harvard"