rampart vs crenelation

rampart and crenelation both are nouns.

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

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

rampart: an embankment built around a space for defensive purposes
crenelation: a rampart built around the top of a castle with regular gaps for firing arrows or guns

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

rampart (noun)	crenelation (noun)
an embankment built around a space for defensive purposes	the action of constructing ramparts with gaps for firing guns or arrows
	a rampart built around the top of a castle with regular gaps for firing arrows or guns