The Collaborative International Dictionary of English v.0.48:

Semeiological \Se`mei*o*log"ic*al\, or Semiologioal
\Se`mi*o*log"io*al\, a.
   Of or pertaining to the science of signs, or the systematic
   use of signs; as, a semeiological classification of the signs
   or symptoms of disease; a semeiological arrangement of signs
   used as signals.
   [1913 Webster] Semeiology