boundary line vs delimitation

boundary line and delimitation both are nouns.

Word	Noun	Adjective	Verb	Adverb
boundary line	Yes	No	No	No
delimitation	Yes	No	No	No

As nouns, boundary line and delimitation are synonyms defined as:

Other synonyms of boundary line include border, borderline, mete.

boundary line (noun)	delimitation (noun)
a line that indicates a boundary	a line that indicates a boundary