rampart vs earthwork

rampart and earthwork both are nouns.

Word	Noun	Adjective	Verb	Adverb
rampart	Yes	No	No	No
earthwork	Yes	No	No	No

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

Other hyponyms of rampart include bailey, battlement, crenelation, crenellation, fraise, merlon.

rampart (noun)	earthwork (noun)
an embankment built around a space for defensive purposes	an earthen rampart