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ordinal number

American  

noun

ordinal numbers plural
  1. 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).

  2. 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.


ordinal number British  

noun

  1. Sometimes shortened to: ordinal.  a number denoting relative position in a sequence, such as first, second, third

  2. 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

ordinal number Scientific  
/ ôrdn-əl /
  1. A number, such as 3rd, 11th, or 412th, used in counting to indicate position in a series but not quantity.

  2. Compare cardinal number


Other Word Forms

Noun Inflected Forms

Etymology

Origin of ordinal number

First recorded in 1600–10

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

There are 25 Helena Drives in Brentwood, each a cul-de-sac preceded by a different ordinal number — 7th, 19th, etc.

From Los Angeles Times Jul. 17, 2024

But they also define a school’s place in higher education through a single ordinal number derived from a subjective formula.

From Washington Post

Elev′enth, the ordinal number corresponding to eleven.—Eleventh hour, the very last moment, referring to Matt. xx.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various

That is, of every compound ordinal number, the last term only is ordinal in form.

From The Grammar of English Grammars by Brown, Goold

He was not given the title of king, and no ordinal number followed his name.

From Penguin Island by France, Anatole

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