ordinal
or-di-nal
adjective
Relating to a number indicating position or order in a sequence.
"The word 'first' is an ordinal number."
Thesaurus
Synonyms: 35th, 64th, twenty-sixth, hundred-and-fifty-fifth, 32nd, quintillionth, 4th, 500th, 2nd, eighteenth, 39th, 26th
Antonyms: cardinal