ordinal number


noun

Also called ordinal numeral. any of the numbers that express degree, quality, or position in a series, as first, second, and third (distinguished from cardinal number).
Mathematics. a symbol denoting both the cardinal number and the ordering of a given set, being identical for two ordered sets having elements that can be placed into one-to-one correspondence, the correspondence preserving the order of the elements.

Nearby words

  1. orderly officer,
  2. orderly room,
  3. orders,
  4. orders, holy,
  5. ordinal,
  6. ordinal numbers,
  7. ordinal scale,
  8. ordinance,
  9. ordinand,
  10. ordinariate

Origin of ordinal number

First recorded in 1600–10

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019


British Dictionary definitions for ordinal number

ordinal number

noun

a number denoting relative position in a sequence, such as first, second, thirdSometimes shortened to: ordinal
logic maths a measure of not only the size of a set but also the order of its elements

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

Science definitions for ordinal number

ordinal number

[ôrdn-əl]

A number, such as 3rd, 11th, or 412th, used in counting to indicate position in a series but not quantity. Compare cardinal number.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.