substantiation

something presented in support of the truth or accuracy of a claim <the signature of a witness provides substantiation that a person's will is genuine> Synonyms attestation, confirmation, corroboration, documentation, evidence, proof, testament, testimonial, testimony, validation, voucher, witnessRelated Words (the) goods; certificate, document, exhibit; demonstration, illustration; authentication, identification, manifestation, verificationNear Antonyms rebuttal, refutation; accusation, allegation, charge; assumption, conjecture, guess, presumption, surmise, suspicionAntonyms disproof