The Collaborative International Dictionary of English v.0.48:

Classify \Clas"si*fy\, v. t. [imp. & p. p. Classified; p. pr.
   & vb. n. Classifying.] [L. classis class + -fy.]
   To distribute into classes; to arrange according to a system;
   to arrange in sets according to some method founded on common
   properties or characters.

   Syn: To arrange; distribute; rank.
        [1913 Webster]