remorse
n. uncountablen. a strong feeling of sadness and regret for doing something wrong. It is deeper than just feeling sorry because you feel guilty about the harm you caused.
n. a deep and painful sense of regret or guilt for past wrongs. Often implies a moral or spiritual distress rather than just social embarrassment.
He felt deep remorse for his unkind words.
The defendant showed no remorse during the trial, which led the judge to issue a harsher sentence.
True remorse involves not only the internal agony of guilt but also a sincere desire to make amends to those who were harmed by one's actions.
First attested circa 14th century as Middle English remors, from Old French remors, from Medieval Latin remorsus, from Latin remordeō (“to torment, vex”, literally “to bite back”), from re- + mordeō (“to bite”). More at remord.
Commonly follows the verbs 'feel', 'show', or 'express'; often paired with the preposition 'for'.