Definitions of regret:
- noun: sadness associated with some wrong done or some disappointment
Example: "He wrote a note expressing his regret"
- verb: be sorry
Example: "I regret to say that you did not gain admission to Harvard"
- verb: decline formally or politely
Example: "I regret I can't come to the party"
- verb: feel sad about the loss or absence of
- verb: feel remorse for; feel sorry for; be contrite about