raiment vs overdress

raiment is a noun but overdress is not a noun.

Word	Noun	Adjective	Verb	Adverb
raiment	Yes	No	Yes	No
overdress	No	No	Yes	No

As verbs, overdress is a hyponym of raiment; that is, overdress is a word with a more specific, narrower meaning than raiment:

raiment (noun)	overdress (noun)
especially fine or decorative clothing

raiment (verb)	overdress (verb)
provide with clothes or put clothes on	put on special clothes to appear particularly appealing and attractive
	dress too warmly