'Napier's bones' definitions:

Definition of 'Napier's bones'

From: WordNet
noun
A set of graduated rods formerly used to do multiplication and division by a method invented by John Napier [syn: Napier's bones, Napier's rods]

Definition of 'Napier's bones'

From: GCIDE
  • Napier's bones \Na"pi*er's bones`\, Napier's rods \Na"pi*er's rods`\ A set of rods, made of bone or other material, each divided into nine spaces, and containing the numbers of a column of the multiplication table; -- a contrivance of Baron Napier, the inventor of logarithms, for facilitating the operations of multiplication and division. [1913 Webster]