1. A polite refusal of an invitation
   "He sent his regrets that he couldn't attend the wedding";
   - declination

1. Sadness associated with some wrong done or some disappointment
   "he wrote a note expressing his regret";
   - sorrow, rue [archaic], ruefulness

1. Feel remorse for; feel sorry for; be contrite about
   "She regretted the day she quit her job";
   - repent, rue
    
2. Feel sad about the loss or absence of
   "She regretted not saying goodbye to her grandmother"
    
3. Express with regret
   "I regret to say that you did not gain admission to Harvard"
    
4. Decline formally or politely
   "I regret I can't come to the party"

Type of: acknowledgement, acknowledgment, decline, experience, feel, inform, miss, refusal, refuse, sadness, unhappiness

Encyclopedia: Regrets