regret

(noun) sadness associated with some wrong done or some disappointment. Synonyms: sorrow, rue, ruefulness. Examples: "He drank to drown his sorrows." "He wrote a note expressing his regret." "To his rue, the error cost him the game."

(verb) feel remorse for; feel sorry for; be contrite about. Synonyms: repent, rue.

(verb) feel sad about the loss or absence of.

(verb) decline formally or politely. Example: "I regret i can't come to the party."

(verb) express with regret. Example: "I regret to say that you did not gain admission to harvard."