barrier vs curtain

barrier and curtain both are nouns.

Word	Noun	Adjective	Verb	Adverb
barrier	Yes	No	No	No
curtain	Yes	No	Yes	No

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

barrier: anything serving to maintain separation by obstructing vision or access
curtain: any barrier to communication or vision

Other hyponyms of barrier include bar, blood-brain barrier.

barrier (noun)	curtain (noun)
a structure or object that impedes free movement	hanging cloth used as a blind (especially for a window)
any condition that makes it difficult to make progress or to achieve an objective	any barrier to communication or vision
anything serving to maintain separation by obstructing vision or access

barrier (verb)	curtain (verb)
	provide with drapery