remain vs remnant

remain is not a noun while remnant is a noun.

Word	Noun	Adjective	Verb	Adverb
remain	No	No	Yes	No
remnant	Yes	No	No	No

remain (noun)	remnant (noun)
	a piece of cloth that is left over after the rest has been used or sold
	a small part or portion that remains after the main part no longer exists

remain (verb)	remnant (verb)
stay the same; remain in a certain state
be in a certain place and not leave
continue in a place, position, or situation
be left; of persons, questions, problems, results, evidence, etc.