| 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 a 1, a2, … an is n. |
| cardinal number n. A number, such as 3 or 11 or 412, used in counting to indicate quantity but not order. |
cardinal number  (kär'dn-əl) Pronunciation Key
A number, such as 3, 11, or 412, used in counting to indicate quantity but not order. Compare ordinal number. |
cardinal number
The cardinality of some set.