1.nounAn ordinal number such as first, second and third.
"The most common numerals in Latin, as in English, are the "cardinals"...and the "ordinals"... — F. M. Wheelock, Wheelock’s Latin, 6th ed. revised (2005), p97"
2.nounA book used in the ordination of Anglican ministers, or in certain Roman Catholic services
3.adjective(of a number) indicating position in a sequence
4.adjectiveOf or relating to the groupings called orders