The Collaborative International Dictionary of English v.0.48:

Chirology \Chi*rol"o*gy\, n. [Gr. chei`r hand + -logy.]
   The art or practice of using the manual alphabet or of
   communicating thoughts by sings made by the hands and
   fingers; a substitute for spoken or written language in
   intercourse with the deaf and dumb. See Dactylalogy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chirology
    n 1: telling fortunes by lines on the palm of the hand [syn:
         palmistry, palm reading, chiromancy, chirology]