Provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes:
— His high fever attested to his illness.

synonyms: certify, demonstrate, evidence, manifest.

Roget 768: promise; give a promise etc. n.; undertake, engage; make an engagement, form an engagement; enter into an engagement, enter on an engagement; bind oneself, tie oneself, pledge oneself, commit oneself, take upon oneself; vow; swear etc. (affirm) 535, give one's word, pass one's word, pledge one's word, plight one's word, give one's honor, pass one's honor, pledge one's honor, plight one's honor, give credit, pass credit, pledge credit, plight credit, give troth, pass troth, pledge troth, plight troth; betroth, plight faith.    assure, warrant, guarantee; covenant etc. 769; attest etc. (bear witness) 467.    hold out an expectation; contract an obligation; become bound to, become sponsor for; answer for, be answerable for; secure; give security etc. 771; underwrite.    adjure, administer an oath, put to one's oath, swear a witness.    ... show more

Roget 535: assert; make an assertion etc. n.; have one's say; say, affirm, predicate, declare, state; protest, profess.    put forth, put forward; advance, allege, propose, propound, enunciate, broach, set forth, hold out, maintain, contend, pronounce, pretend.    depose, depone, aver, avow, avouch, asseverate, swear; make oath, take one's oath; make an affidavit, swear an affidavit, put in an affidavit; take one's Bible oath, kiss the book, vow, vitam impendere vero [Lat.]; swear till one is black in the face, swear till one is blue in the face, swear till all's blue; be sworn, call Heaven to witness; vouch, warrant, certify, assure, swear by bell book and candle.    swear by etc. (believe) 484; insist upon, take one's stand upon; emphasize, lay stress on; assert roundly, assert positively; lay down, lay down the law; raise one's voice, dogmatize, have the last word; rap out; repeat; reassert, reaffirm.    announce etc. (information) 527; acknowledge etc. (assent) 488; attest etc. (evidence) 467; adjure etc. (put to one's oath) 768.    ... show more

Dutch: betogen, demonstreren, manifesteren

Authenticate, affirm to be true, genuine, or correct, as in an official capacity.

Dutch: attesteren

Give testimony in a court of law.

synonyms: bear witness, take the stand, testify.

Roget 550: indicate; be the sign etc. n.. of; denote, betoken; argue, testify etc. (evidence) 467; bear the impress etc. n.. of; connote, connotate^†.    represent, stand for; typify etc. (prefigure) 511; symbolize.    put an indication, put a mark etc. n.; note, mark, stamp, earmark; blaze; label, ticket, docket; dot, spot, score, dash, trace, chalk; print; imprint, impress; engrave, stereotype.    make a sign etc. n.. signalize; underscore; give a signal, hang out a signal; beckon; nod; wink, glance, leer, nudge, shrug, tip the wink; gesticulate; raise the finger, hold up the finger, raise the hand, hold up the hand; saw the air, suit the action to the word" [Hamlet]. wave a banner, unfurl a banner, hoist a banner, hang out a banner etc. n.; wave the hand, wave a kerchief; give the cue etc. (inform) 527; show one's colors; give an alarm, sound an alarm; beat the drum, sound the trumpets, raise a cry.    sign, seal, attest etc. (evidence) 467; underline etc. (give importance to) 642; call attention to etc. (attention) 457; give notice etc. (inform) 527.    ... show more

Roget 467: be evidence etc. n.; evince, show, betoken, tell of; indicate etc. (denote) 550; imply, involve, argue, bespeak, breathe.    have weight, carry weight; tell, speak volumes; speak for itself etc. (manifest) 525.    rest upon, depend upon; repose on.    bear witness etc. n.; give evidence etc. n.; testify, depose, witness, vouch for; sign, seal, undersign^†, set one's hand and seal, sign and seal, deliver as one's act and deed, certify, attest; acknowledge etc. (assent) 488.    [provide conclusive evidence] make absolute, confirm, prove (demonstrate) 478.    [add further evidence] indorse, countersign, corroborate, support, ratify, bear out, uphold, warrant.    adduce, attest, cite, quote; refer to, appeal to; call, call to witness; bring forward, bring into court; allege, plead; produce witnesses, confront witnesses.    place into evidence, mark into evidence.    [obtain evidence] collect evidence, bring together evidence, rake up evidence; experiment etc. 463.    have a case, make out a case; establish, authenticate, substantiate, verify, make good, quote chapter and verse; bring home to, bring to book.    ... show more

Dutch: getuigen

Establish or verify the usage of.