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.

Origin of ordinal number

First recorded in 1600–10

Words Nearby ordinal number

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ordinal number in a sentence

The first column of each page contains the ordinal number of the disturbance for purposes of reference.
Catalogue of Violent and Destructive Earthquakes in the Philippines | Miguel Saderra Mas
The Latin language often employed the ordinal number instead of the cardinal number.
History of Julius Caesar Vol. 2 of 2 | Napoleon III, Emperor of the French, 1808-1873.
Let P be the ordinal number of one of these rings, for example the first counting from the centre.
Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 6 | Various
Eight′fold, eight times any quantity; Eighth, the ordinal number corresponding to eight.
Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) | Various
Eight′ieth, the ordinal number corresponding to eighty; Eight′y, eight times ten, fourscore.
Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) | Various

British Dictionary definitions for ordinal number

ordinal number

noun

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

Compare cardinal number

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

Scientific definitions for ordinal number

ordinal number

[ ôr′dn-əl ]

A number, such as 3rd, 11th, or 412th, used in counting to indicate position in a series but not quantity. Compare cardinal number.

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