undress vs disrobe

undress is a noun but disrobe is not a noun.

Word	Noun	Adjective	Verb	Adverb
undress	Yes	No	Yes	No
disrobe	No	No	Yes	No

As verbs, undress and disrobe are synonyms defined as:

Other synonyms of undress include discase, peel, strip, strip down, uncase, unclothe.

undress (noun)	disrobe (noun)
partial or complete nakedness

undress (verb)	disrobe (verb)
get undressed	get undressed
remove (someone's or one's own) clothes