dress vs costume

dress and costume both are nouns.

Word	Noun	Adjective	Verb	Adverb
dress	Yes	Yes	Yes	No
costume	Yes	No	Yes	No

As nouns, costume is a hyponym of dress; that is, costume is a word with a more specific, narrower meaning than dress:

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

dress (noun)	costume (noun)
a one-piece garment for a woman; has skirt and bodice	the attire worn in a play or at a fancy dress ball
clothing of a distinctive style or for a particular occasion	the attire characteristic of a country or a time or a social class
clothing in general	unusual or period attire not characteristic of or appropriate to the time and place
	the prevalent fashion of dress (including accessories and hair style as well as garments)

dress (adjective)	costume (adjective)
(of an occasion) requiring formal clothes
suitable for formal occasions

dress (verb)	costume (verb)
put on clothes	dress in a costume
provide with clothes or put clothes on	furnish with costumes; as for a film or play
apply a bandage or medication to
arrange attractively
dress or groom with elaborate care
give a neat appearance to
dress in a certain manner
kill and prepare for market or consumption
convert into leather
put a dressing on
put a finish on
cultivate, tend, and cut back the growth of
provide with decoration
cut down rough-hewn (lumber) to standard thickness and width
decorate (food), as with parsley or other ornamental foods
arrange in ranks