Source : Webster's Revised Unabridged Dictionary (1913)

Effort \Ef"fort\, v. t.
   To stimulate. [Obs.] ``He efforted his spirits.'' --Fuller.

Effort \Ef"fort\, n. [F. effort, OF. esfort, for esfors, esforz,
   fr. esforcier. See {Efforce}.]
   1. An exertion of strength or power, whether physical or
      mental, in performing an act or aiming at an object; more
      or less strenuous endeavor; struggle directed to the
      accomplishment of an object; as, an effort to scale a
      wall.

            We prize the stronger effort of his power. --Pope.

   2. (Mech.) A force acting on a body in the direction of its
      motion. --Rankine.

   Syn: Endeavor; exertion; struggle; strain; straining;
        attempt; trial; essay. See {Attempt}.

Source : WordNet®

effort
     n 1: earnest and conscientious activity intended to do or
          accomplish something; "made an effort to cover all the
          reading material"; "wished him luck in his endeavor";
          "she gave it a good try" [syn: {attempt}, {endeavor}, {endeavour},
           {try}]
     2: use of physical or mental energy; hard work; "he got an A
        for effort"; "they managed only with great exertion" [syn:
         {elbow grease}, {exertion}, {travail}, {sweat}]
     3: a series of actions advancing a principle or tending toward
        a particular end; "he supported populist campaigns"; "they
        worked in the cause of world peace"; "the team was ready
        for a drive toward the pennant"; "the movement to end
        slavery"; "contributed to the war effort" [syn: {campaign},
         {cause}, {crusade}, {drive}, {movement}]
     4: a notable achievement; "he performed a great deed"; "the
        book was her finest effort" [syn: {deed}, {feat}, {exploit}]