Source : Webster's Revised Unabridged Dictionary (1913)

Optimistic \Op`ti*mis"tic\, a.
   1. (Metaph.) Of or pertaining to optimism; tending, or
      conforming, to the opinion that all events are ordered for
      the best.

   2. Hopeful; sanguine; as, an optimistic view.

Source : WordNet®

optimistic
     adj 1: expecting the best in this best of all possible worlds; "in
            an optimistic mood"; "optimistic plans"; "took an
            optimistic view" [ant: {pessimistic}]
     2: expecting the best; "an affirmative outlook" [syn: {affirmative}]