cryptical in WordNet English dictionary

1. having a secret or hidden meaning
   "cabalistic symbols engraved in stone"; "cryptic writings"; "thoroughly sibylline in most of his pronouncements"- John Gunther
   cabalistic  kabbalistic  qabalistic  cryptic  cryptical  sibylline 
   
2. of an obscure nature
   "the new insurance policy is written without cryptic or mysterious terms"; "a deep dark secret"; "the inscrutable 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"
   cryptic  cryptical  deep  inscrutable  mysterious  mystifying