1. establish the authenticity of something
The Collaborative International Dictionary of English v.0.48:
Authenticate \Au*then"ti*cate\, v. t. [imp. & p. p.
Authenticated; p. pr. & vb. n. Authenticating (?).] [Cf.
1. To render authentic; to give authority to, by the proof,
attestation, or formalities required by law, or sufficient
to entitle to credit.
The king serves only as a notary to authenticate the
choice of judges. --Burke.
2. To prove authentic; to determine as real and true; as, to
authenticate a portrait. --Walpole.
WordNet (r) 3.0 (2006):
v 1: establish the authenticity of something
Moby Thesaurus II by Grady Ward, 1.0:
66 Moby Thesaurus words for "authenticate":
OK, accept, accredit, affirm, amen, approve, attest, authorize,
autograph, avouch, back, back up, bear out, bolster, buttress,
certify, circumstantiate, confirm, corroborate, cosign,
countersign, demonstrate, document, endorse, fortify,
give permission, give the go-ahead, give the imprimatur,
give thumbs up, initial, justify, notarize, pass, pass on,
pass upon, permit, probate, prove, ratify, reinforce, rubber stamp,
sanction, say amen to, seal, second, sign, sign and seal,
strengthen, subscribe to, substantiate, support, sustain,
swear and affirm, swear to, test, try, undergird, undersign,
underwrite, uphold, validate, verify, visa, vise, vouch for,