ordinal number

noun

1. Also called ordinal numeral. any of the numbers that express degree, quality, or position in a series, as first, second, and third (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

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

ordinal number

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

Word History and Origins

Origin of ordinal number¹

First recorded in 1600–10