| Corroborate (v. t.) To confirm a proof or conjecture; to make more certain; to confirm; as, to corroborate the testimony of a witness. Thesaurus Entries affirm, attest, authenticate, back, back up, bear out, bolster, buttress, certify, circumstantiate, confirm, document, fortify, justify, probate, prove, ratify, reinforce, strengthen, substantiate, support, sustain, undergird, uphold, validate, verify, warrant |