substantiate

confirm, corroborate, substantiate, verify, authenticate, validate mean to attest to the truth or validity of something. confirm implies the removing of doubts by an authoritative statement or indisputable fact. confirmed the reports corroborate suggests the strengthening of what is already partly established. witnesses corroborated his story substantiate implies the offering of evidence that sustains the contention. the claims have yet to be substantiated verify implies the establishing of correspondence of actual facts or details with those proposed or guessed at. all statements of fact in the article have been verified authenticate implies establishing genuineness by adducing legal or official documents or expert opinion. handwriting experts authenticated the diaries validate implies establishing validity by authoritative affirmation or by factual proof. validated the hypothesis by experiments