copestone vs finishing touch

copestone and finishing touch both are nouns.

Word	Noun	Adjective	Verb	Adverb
copestone	Yes	No	No	No
finishing touch	Yes	No	No	No

As nouns, copestone and finishing touch are synonyms defined as:

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

Other synonyms of copestone include capstone.

copestone (noun)	finishing touch (noun)
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