Synonyms for Attest to:

• v.

  •acknowledge (verb)
  • approve,
  • certify,
  • allow,
  • yield,
  • take an oath,
  • agree,
  • ratify,
  • endorse,
  • recognize,
  • defend,
  • grant,
  • support,
  • subscribe to,
  • uphold,
  • acquiesce,
  • defer to,
  • own.
  •back up a statement, idea (verb)
  • substantiate.
  •give assurance (verb)
  • vouch.
  •substantiate (verb)
  • reify,
  • try on,
  • check out,
  • try out,
  • demonstrate,
  • materialize,
  • check up,
  • actualize,
  • incarnate,
  • personify,
  • objectify,
  • establish,
  • justify,
  • realize,
  • debunk,
  • test,
  • complete,
  • try,
  • prove,
  • manifest.
  •vouch (verb)
  • avow,
  • witness,
  • assert,
  • asseverate,
  • predicate,
  • profess,
  • stand up for,
  • bear testimony,
  • get behind,
  • testify,
  • declare,
  • avert,
  • maintain,
  • be responsible for,
  • say so,
  • sign for,
  • put forth,
  • vow,
  • cosign,
  • answer for,
  • okay,
  • contend,
  • give an affidavit,
  • warrant,
  • rubber-stamp,
  • act as a witness,
  • swear up and down.

• Other synonyms:

  •substantiate
  • Incarnated,
  • trying on,
  • reifies,
  • Incarnating,
  • incarnates.
  •Other relevant words:
  • evince,
  • acknowledge,
  • bear out,
  • authenticate,
  • make certain,
  • promise,
  • stand behind,
  • bear witness,
  • warranty,
  • sponsor,
  • guaranty,
  • assure,
  • corroborate,
  • undertake,
  • vouch for,
  • affirm,
  • confirm,
  • verify,
  • ensure,
  • guarantee,
  • back,
  • make sure,
  • pledge,
  • swear to,
  • validate.

Antonyms for Attest to:

• v.

  • acknowledge
    decline, reject, veto, dispute, invalidate, protest, abjure, ignore, disallow, deny, repudiate, condemn, disagree, oppose, disregard, renounce, disapprove, forswear, contradict, disavow, refuse.
  • substantiate
    disprove, neglect, discredit, break.
  • vouch
    discourage, refute, disclaim, desert.