capstone vs copestone

capstone and copestone both are nouns.

Word	Noun	Adjective	Verb	Adverb
capstone	Yes	No	No	No
copestone	Yes	No	No	No

As nouns, capstone and copestone are synonyms defined as:

Other synonyms of capstone include coping stone, stretcher.

As nouns, capstone and copestone are synonyms defined as:

capstone and copestone: a final touch; a crowning achievement; a culmination

Other synonyms of capstone include finishing touch.

capstone (noun)	copestone (noun)
a stone that forms the top of wall or building	a stone that forms the top of wall or building
a final touch; a crowning achievement; a culmination	a final touch; a crowning achievement; a culmination