1. deplore, lament, bewail, bemoan, mourn, sorrow, grieve. Regret, penitence, remorse imply a sense of sorrow about events in the past, usually wrongs committed or errors made. Regret is distress of mind, sorrow for what has been done or failed to be done: to have no regrets. Penitence implies a sense of sin or misdoing, a feeling of contrition and determination not to sin again: a humble sense of penitence. Remorse implies pangs, qualms of conscience, a sense of guilt, regret, and repentance for sins committed, wrongs done, or duty not performed: a deep sense of remorse.