attest
verb
at·test ə-ˈtest 
attested; attesting; attests
transitive verb
1
a
: to affirm to be true or genuine
specifically : to authenticate by signing as a witness
b
: to authenticate officially
2
: to establish or verify the usage of
a word that was first attested in the 18th century
3
: to be proof of : manifest
Her record attests her integrity.
4
: to put on oath
intransitive verb
: to show, prove, or state that something is true or real —usually used with to
I can attest to the truth of his statement.attest to a belief
attester
ə-ˈte-stər
noun 
Synonyms
- authenticate
- avouch
- certify
- testify (to)
- vouch (for)
- witness
See all Synonyms & Antonyms 
Example Sentences
I can attest that what he has said is true. The certificate attests the authenticity of the painting.
Recent Examples on the Web Her skepticism is fair, as Children of the Underground might attest. 
Sophie Gilbert, The Atlantic, 1 Sep. 2022 Those other extracurricular activities might be even more impressive than being a two-year starter at right guard, and Penny is plenty good at that, as his teammates can attest. Matt Le Cren, Chicago Tribune, 1 Sep. 2022 As those of us who lived through the decade can attest, this is actually period-appropriate. Chris Willman, Variety, 31 Aug. 2022 As generations of twentieth-century Italian mothers and their children can attest, giving a woman no choice but to anonymously surrender her baby is a route to ruined lives. Maria Laurino, The New Republic, 25 Aug. 2022 But finding the right candidate takes time, as Oregon State can attest. oregonlive, 11 Aug. 2022 As with Murray, the question of Williamson’s talent was as clear as day, as anyone who has seen him at full strength and marveled at the remarkable agility of the big man can attest. Don Yaeger, Forbes, 9 Aug. 2022 As anyone who has recently applied for a passport can attest, U.S. passport agencies are still catching up from the pandemic lockdown. Amanda Foreman, WSJ, 12 Aug. 2022 As anyone who’s out and about can attest, though, many Californians are not heeding that call. Luke Money, Los Angeles Times, 21 July 2022 See More
Sophie Gilbert, The Atlantic, 1 Sep. 2022 Those other extracurricular activities might be even more impressive than being a two-year starter at right guard, and Penny is plenty good at that, as his teammates can attest. Matt Le Cren, Chicago Tribune, 1 Sep. 2022 As those of us who lived through the decade can attest, this is actually period-appropriate. Chris Willman, Variety, 31 Aug. 2022 As generations of twentieth-century Italian mothers and their children can attest, giving a woman no choice but to anonymously surrender her baby is a route to ruined lives. Maria Laurino, The New Republic, 25 Aug. 2022 But finding the right candidate takes time, as Oregon State can attest. oregonlive, 11 Aug. 2022 As with Murray, the question of Williamson’s talent was as clear as day, as anyone who has seen him at full strength and marveled at the remarkable agility of the big man can attest. Don Yaeger, Forbes, 9 Aug. 2022 As anyone who has recently applied for a passport can attest, U.S. passport agencies are still catching up from the pandemic lockdown. Amanda Foreman, WSJ, 12 Aug. 2022 As anyone who’s out and about can attest, though, many Californians are not heeding that call. Luke Money, Los Angeles Times, 21 July 2022 See More Word History
Etymology
Middle French attester, from Latin attestari, from ad- + testis witness — more at testament
First Known Use
circa 1500, in the meaning defined at transitive sense 1a
Kids Definition
attest
verb
at·test ə-ˈtest
attested; attesting
: to show or give proof of : say to be true
I can attest to his innocence.
Legal Definition
attest
verb
at·test ə-ˈtest
transitive verb
: to bear witness to : affirm to be true or genuine
specifically : to authenticate (as a will) by signing as a witness
intransitive verb
: to bear witness : testify —often used with to
attesting
verb
1
as in certifying
to declare (something) to be true or genuine the appraiser attests that the lamp is indeed an original Tiffany Synonyms & Similar Words
Relevance
- certifying
- affirming
- guaranteeing
- authenticating
- witnessing
- asserting
- testifying (to)
- averring
- professing
- vouching (for)
- avouching
- avowing
- warranting
- vowing
2
as in testifying
to make a solemn declaration under oath for the purpose of establishing a fact an eyewitness who will attest to my innocence Synonyms & Similar Words
- testifying
- verifying
- witnessing
- swearing
- bearing witness
- vouching
- deposing
- promising
- vowing
3
as in confirming
to give evidence or testimony to the truth or factualness of I'll attest that she was at the party Synonyms & Similar Words
- confirming
- verifying
- supporting
- arguing
- corroborating
- certifying
- proving
- validating
- demonstrating
- substantiating
- authenticating
- vindicating
- witnessing
- affirming
- bearing out
- reinforcing
- establishing
- documenting
- asserting
- declaring
- guaranteeing
- professing
- averring
- warranting
- avowing
- testifying (to)
- avouching
- vouching (for)
- reenforcing
- backing (up)
Antonyms & Near Antonyms
- refuting
- disproving
- contradicting
- rebutting
- denying
- disclaiming
- disavowing
- disputing
- questioning
- contesting
- challenging
- gainsaying