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 (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.
Origin
1600-10
Examples from the web for ordinal number
  • Shows the ordinal number of the current page and the total number of pages in the plot file.
  • Students may also be asked to determine whether a quantifier should be a cardinal or ordinal number.
  • Count an ordered set of objects, using the ordinal number words first through twentieth.
British Dictionary definitions for ordinal number

ordinal number

noun
1.
a number denoting relative position in a sequence, such as first, second, third Sometimes shortened to ordinal
2.
(logic, maths) a measure of not only the size of a set but also the order of its elements
Compare cardinal number
ordinal number in Science
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.