substantiation vs verification

substantiation and verification both are nouns.

Word	Noun	Adjective	Verb	Adverb
substantiation	Yes	No	No	No
verification	Yes	No	No	No

As nouns, substantiation and verification are synonyms defined as:

substantiation and verification: additional proof that something that was believed (some fact or hypothesis or theory) is correct

Other synonyms of substantiation include check, confirmation.

substantiation (noun)	verification (noun)
the act of validating; finding or testing the truth of something	additional proof that something that was believed (some fact or hypothesis or theory) is correct
additional proof that something that was believed (some fact or hypothesis or theory) is correct	(law) an affidavit attached to a statement confirming the truth of that statement