The Collaborative International Dictionary of English v.0.48:

Geomancy \Ge"o*man`cy\, n. [OE. geomance, geomancie, F.
   g['e]omance, g['e]omancie, LL. geomantia, fr. Gr. ge`a, gh^,
   the earth + mantei`a divination.]
   A kind of divination by means of figures or lines, formed by
   little dots or points, originally on the earth, and latterly
   on paper. Geomantic

WordNet (r) 3.0 (2006):

geomancy
    n 1: divination by means of signs connected with the earth (as
         points taken at random or the arrangement of particles
         thrown down at random or from the configuration of a region
         and its relation to another)