ordinal vs forty-first

ordinal is a noun but forty-first is not a noun.

Word	Noun	Adjective	Verb	Adverb
ordinal	Yes	Yes	No	No
forty-first	No	Yes	No	No

ordinal (noun)	forty-first (noun)
the number designating place in an ordered sequence

ordinal (adjective)	forty-first (adjective)
being or denoting a numerical order in a series	the ordinal number of forty-one in counting order
of or relating to a taxonomic order