regret, ruefulness, sorrow, rue - 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"

guilt feelings, guilt trip, guilty conscience, guilt - remorse caused by feeling responsible for some offence

penance, penitence, repentance - remorse for your past conduct

reproach - a mild rebuke or criticism; "words of reproach"