Source : Webster's Revised Unabridged Dictionary (1913)

Motivate \Mo"ti*vate\, v. t. [imp. & p. p. {-vated}; p. pr. &
   vb. n. {-vating}.] [From {Motive}, n.]
   To provide with a motive; to move; impel; induce; incite. --
   {Mo`ti*va"tion}, n. --William James.

Source : WordNet®

motivation
     n 1: the psychological feature that arouses an organism to action
          toward a desired goal; the reason for the action; that
          which gives purpose and direction to behavior; "we did
          not understand his motivation"; "he acted with the best
          of motives" [syn: {motive}, {need}]
     2: the condition of being motivated; "his motivation was at a
        high level"
     3: the act of motivating; providing incentive [syn: {motivating}]