quartile
         n 1: (statistics) any of three points that divide an ordered
               distribution into four parts each containing one quarter of
               the scores

English Dictionary: quartelada	by the DICT Development Group
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Quartile \Quar"tile\, n. [F. quartile aspect, fr. L. quartus the       fourth. See {Quart}.] (Astrol.)       Same as {Quadrate}.