avouch

1 to declare (something) to be true or genuine <a note from my doctor avouching that my medical condition did indeed disqualify me from gym class> Synonyms attest, authenticate, certify, testify (to), vouch (for), witnessRelated Words guarantee, warrant; affirm, assert, aver, avow, profess, vow

2 to state as a fact usually forcefully <avouched that he had never cheated on his taxes in his life> Synonyms affirm, allege, assert, aver, claim, avow, contend, declare, insist, maintain, profess, protest, purport, warrantRelated Words announce, broadcast, proclaim; argue, rationalize, reason; confirm, justify, vindicate; defend, persevere, support, uphold; reaffirm, reassertNear Antonyms abandon; disavow, disclaim, disown, negate, negative, reject, repudiate; challenge, dispute, question; confute, disprove, rebut, refute; contradict, counterAntonyms deny, gainsay

3 to state clearly and strongly <she tends to avouch her opinions in such a way as to imply that anyone who thinks otherwise is an idiot> Synonyms affirm, aver, assert, avow, declare, guarantee, lay down, professRelated Words advance, advertise, boost, plug, promote, publicize; announce, blaze, call, proclaim, pronounce, say; accent, accentuate, emphasize, stress, underline, underscore; advocate, champion, defend, espouse, support, uphold; assure, convince, persuade; explain, justify, rationalize; reaffirm, reassertNear Antonyms minimize, understate; disregard, ignore, neglect, overlook