Napier's bones

noun (used with a singular verb) Mathematics.

a form of multiplication table originally marked on sticks of bone or ivory that could be rearranged to carry out the operations of multiplication or division.

Origin of Napier's bones

First recorded in 1650–60; after their developer, J. Napier
Also called Napier's rods. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for napier's bones

Napier's bones

pl n

a set of graduated rods formerly used for multiplication and division

Word Origin for Napier's bones

C17: based on a method invented by John Napier
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012