Source : Webster's Revised Unabridged Dictionary (1913)

Forgo \For*go"\, v. t. [imp. {Forwent}; p. p. {Forgone}; p. pr.
   & vb. n. {Forgoing}.] [OE. forgan, forgon, forgoon, AS.
   forg[=a]n, prop., to go past, hence, to abstain from; pref.
   for- + g[=a]n to go; akin to G. vergehen to pass away, to
   transgress. See {Go}, v. i.]
   To pass by; to leave. See 1st {Forego}.

         For sith [since] I shall forgoon my liberty At your
         request.                                 --Chaucer.

         And four [days] since Florimell the court forwent.
                                                  --Spenser.

   Note: This word in spelling has been confused with, and
         almost superseded by, forego to go before.
         Etymologically the form forgo is correct.

Source : WordNet®

forgoing
     n : the act of renouncing; sacrificing or giving up or
         surrendering (a possession or right or title or privilege
         etc.) [syn: {renunciation}, {forswearing}]