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

“Foot,” i.e. foot-soldier, was 617 formerly, with an ordinal number prefixed, the name of the infantry regiments of the British army.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" 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

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