Source : Webster's Revised Unabridged Dictionary (1913)

Regret \Re*gret"\, v. t. [imp. & p. p. {Regretted} (-t[e^]d); p.
   pr. & vb. n. {Regretting}.] [F. regretter, OF. regreter; L.
   pref. re- re- + a word of Teutonic origin; cf. Goth.
   gr[=e]tan to weep, Icel. gr[=a]ta. See {Greet} to lament.]
   To experience regret on account of; to lose or miss with a
   sense of regret; to feel sorrow or dissatisfaction on account
   of (the happening or the loss of something); as, to regret an
   error; to regret lost opportunities or friends.

         Calmly he looked on either life, and here Saw nothing
         to regret, or there to fear.             --Pope.

         In a few hours they [the Israelites] began to regret
         their slavery, and to murmur against their leader.
                                                  --Macaulay.

         Recruits who regretted the plow from which they had
         been violently taken.                    --Macaulay.

Source : WordNet®

regret
     v 1: feel remorse for; feel sorry for; be contrite about [syn: {repent},
           {rue}]
     2: feel sad about the loss or absence of
     3: decline formally or politely; "I regret I can't come to the
        party"
     4: be sorry; "I regret to say that you did not gain admission
        to Harvard"
     [also: {regretting}, {regretted}]

regret
     n : sadness associated with some wrong done or some
         disappointment; "he drank to drown his sorrows"; "he
         wrote a note expressing his regret"; "to his rue, the
         error cost him the game" [syn: {sorrow}, {rue}, {ruefulness}]
     [also: {regretting}, {regretted}]

regretting
     See {regret}