The Collaborative International Dictionary of English v.0.48:

Geest \Geest\, n. [Cf. LG. geest, geestland, sandy, dry and,
   OFries. g[=e]st, g[=a]st, g[=e]stlond, g[=a]stlond, fr.
   Fries. g[=a]st barren. Cf. Geason.]
   Alluvial matter on the surface of land, not of recent origin.
   --R. Jameson.
   [1913 Webster]