thousandth vs ordinal

thousandth and ordinal both are nouns.

Word	Noun	Adjective	Verb	Adverb
thousandth	Yes	Yes	No	No
ordinal	Yes	Yes	No	No

thousandth (noun)	ordinal (noun)
one part in a thousand equal parts	the number designating place in an ordered sequence
position 1,000 in a countable series of things

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