Source : Webster's Revised Unabridged Dictionary (1913)

Transitional \Tran*si"tion*al\, a.
   Of or pertaining to transition; involving or denoting
   transition; as, transitional changes; transitional stage.

Source : WordNet®

transitional
     adj : of or relating to or characterized by transition;
           "adolescence is a transitional stage between childhood
           and adulthood"