Source : Webster's Revised Unabridged Dictionary (1913)

Rabdology \Rab*dol"o*gy\, n. [Gr. ? rod, stick + -logy: cf. F.
   rabdologie.]
   The method or art of performing arithmetical operations by
   means of Napier's bones. See {Napier's bones}. [Written also
   {rhabdology}.]