cardinal number

noun
1.
Also called cardinal numeral. any of the numbers that express amount, as one, two, three, etc. (distinguished from ordinal number).
2.
Also called potency, power. Mathematics. a number or symbol analogous to the number of elements in a finite set, being identical for two sets that can be placed into one-to-one correspondence:
The cardinal number of the set a1, a2, … an is n.
Origin
1585-95
Examples from the web for cardinal number
  • What turns a year into a cardinal number is when you consider how many of them there are in any given period.
British Dictionary definitions for cardinal number

cardinal number

noun
1.
a number denoting quantity but not order in a set Sometimes shortened to cardinal
2.
(maths, logic)
  1. a measure of the size of a set that does not take account of the order of its members Compare natural number
  2. a particular number having this function
Compare ordinal number
Word Origin and History for cardinal number
n.

1590s, "one, two, three," etc. as opposed to ordinal numbers "first, second, third," etc.; so called because they are the principal numbers and the ordinals depend on them (see cardinal (adj.)).

cardinal number in Science
cardinal number
  (kär'dn-əl)   
A number, such as 3, 11, or 412, used in counting to indicate quantity but not order. Compare ordinal number.
cardinal number in Technology


The cardinality of some set.