Source : Webster's Revised Unabridged Dictionary (1913)

Cryptic \Cryp"tic\ (kr[i^]p"t[i^]k), Cryptical \Cryp"tic*al\
   (-t?-kal), a. [L. crypticus, Gr. kryptiko`s, fr. kry`ptein to
   hide.]
   Hidden; secret; occult. ``Her [nature's] more cryptic ways of
   working.'' --Glanvill.

Source : WordNet®

cryptic
     adj 1: of an obscure nature; "the new insurance policy is written
            without cryptic or mysterious terms"; "a deep dark
            secret"; "the inscrutible workings of Providence"; "in
            its mysterious past it encompasses all the dim origins
            of life"- Rachel Carson; "rituals totally mystifying
            to visitors from other lands" [syn: {cryptical}, {deep},
             {inscrutable}, {mysterious}, {mystifying}]
     2: having a secret or hidden meaning; "cabalistic symbols
        engraved in stone"; "cryptic writings"; "thoroughly
        sibylline in most of his pronouncements"- John Gunther
        [syn: {cabalistic}, {kabbalistic}, {qabalistic}, {cryptical},
         {sibylline}]
     3: having a puzzling terseness; "a cryptic note"