Source : Webster's Revised Unabridged Dictionary (1913)

Retrace \Re*trace"\, v. t. [Pref. re- + trace: cf. F. retracer.
   Cf. {Retract}.]
   1. To trace back, as a line.

            Then if the line of Turnus you retrace, He springs
            from Inachus of Argive race.          --Driden.

   2. To go back, in or over (a previous course); to go over
      again in a reverse direction; as, to retrace one's steps;
      to retrace one's proceedings.

   3. To trace over again, or renew the outline of, as a
      drawing; to draw again.

Source : WordNet®

retrace
     v 1: to go back over again; "we retraced the route we took last
          summer"; "trace your path" [syn: {trace}]
     2: reassemble mentally; "reconstruct the events of 20 years
        ago" [syn: {reconstruct}, {construct}]