thirty-eighth vs 38th

thirty-eighth and 38th both are adjectives.

Word	Noun	Adjective	Verb	Adverb
thirty-eighth	No	Yes	No	No
38th	No	Yes	No	No

As adjectives, thirty-eighth and 38th are synonyms defined as:

thirty-eighth and 38th: the ordinal number of thirty-eight in counting order

thirty-eighth (adjective)	38th (adjective)
the ordinal number of thirty-eight in counting order	the ordinal number of thirty-eight in counting order