crenellation vs battlement

crenellation and battlement both are nouns.

Word	Noun	Adjective	Verb	Adverb
crenellation	Yes	No	No	No
battlement	Yes	No	No	No

As nouns, crenellation and battlement are synonyms defined as:

crenellation and battlement: a rampart built around the top of a castle with regular gaps for firing arrows or guns

Other synonyms of crenellation include crenelation.

crenellation (noun)	battlement (noun)
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
a rampart built around the top of a castle with regular gaps for firing arrows or guns