barrier vs revetment

barrier and revetment both are nouns.

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

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

barrier (noun)	revetment (noun)
a structure or object that impedes free movement	a facing (usually masonry) that supports an embankment
any condition that makes it difficult to make progress or to achieve an objective	a barrier against explosives
anything serving to maintain separation by obstructing vision or access