ordinal number

American  

noun

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.

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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

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ordinal number Scientific  

/ ôr′dn-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

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Etymology

Origin of ordinal number

First recorded in 1600–10

Example Sentences

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

Where a number is expressed in terms of various denominations, a cardinal number usually begins with the largest denomination, and an ordinal number with the smallest.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 5 "Arculf" to "Armour, Philip" by Various

The first column of each page contains the ordinal number of the disturbance for purposes of reference.

From Catalogue of Violent and Destructive Earthquakes in the Philippines With an Appendix: Earthquakes in the Marianas Islands 1599-1909 by Saderra Masó, Miguel

An ordinal number answers to the question, "Which one?" or, "What one?"

From The Grammar of English Grammars by Brown, Goold