Source : Webster's Revised Unabridged Dictionary (1913)

Ritualistic \Rit`u*al*is"tic\, a.
   Pertaining to, or in accordance with, a ritual; adhering to
   ritualism.

Source : WordNet®

ritualistic
     adj : of or characterized by or adhering to ritualism; "a feudal
           or ritualistic society"; "the ritualistic killing of a
           sheep"