noun.
Something which substantiates; evidence, proof
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
the act of validating; finding or testing the truth of something
noun.
additional proof that something that was believed (some fact or hypothesis or theory) is correct
Word Usage
"I will be pleased to review any information which Mr. McMeans might directly provide in substantiation of your claimed SEAL service and to discuss your claimed credentials at length with him."