certify
Americanverb (used with object)
-
certifies,
present (3rd person singular)
-
certified,
past participle, past
-
certifying
present participle
-
to attest as certain; give reliable information of; confirm.
He certified the truth of his claim.
- Synonyms:
- guarantee, validate, verify, corroborate
-
to testify to or vouch for in writing.
The medical examiner will certify his findings to the court.
-
to guarantee; endorse reliably.
to certify a document with an official seal.
-
to guarantee (a check) by writing on its face that the account against which it is drawn has sufficient funds to pay it.
-
to award a certificate to (a person) attesting to the completion of a course of study or the passing of a qualifying examination.
-
to declare legally insane and committable to a mental institution.
-
Archaic. to assure or inform with certainty.
verb (used without object)
-
certifies,
present (3rd person singular)
-
certified,
past participle, past
-
certifying
present participle
verb
-
to confirm or attest (to), usually in writing
the letter certified her age
-
(tr) to endorse or guarantee (that certain required standards have been met)
-
to give reliable information or assurances
he certified that it was Walter's handwriting
-
(tr) to declare legally insane
-
(tr) (of a bank) to state in writing on (a cheque) that payment is guaranteed
Other Word Forms
Derived Forms
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certifiernoun
-
precertifyverb (used with object)
-
recertifyverb (used with object)
-
uncertifyingadjective
Inflected Forms
Participles
Conjugated Forms
Present
-
certifysimple
-
certifiessimple
-
have certifiedperfect
-
has certifiedperfect
-
am certifyingprogressive
-
are certifyingprogressive
-
is certifyingprogressive
-
have been certifyingperfect progressive
-
has been certifyingperfect progressive
Past
-
certifiedsimple
-
had certifiedperfect
-
was certifyingprogressive
-
were certifyingprogressive
-
had been certifyingperfect progressive
Future
Etymology
Origin of certify
1300–50; Middle English certifien < Middle French certifier < Late Latin certificāre, equivalent to Latin certi- (combining form of certus decided; see certain) + -ficāre -fy
Explanation
To certify is to provide proof for something or to license someone, like a lawyer. You can certify a lawyer or certify that someone’s insane. Either way, when you certify something, you make it official. To certify is to have evidence that something is true, to make certain. If you certify that you own a house, you prove it's yours. Vouching for a friend can certify that the friend is a good person. Professionals like lawyers, doctors, and accountants must be certified. Being certified assures others that the person is qualified. Certify also refers to declaring someone legally insane, so make sure your doctor is certified by the medical board, not the loony bin.
Vocabulary lists containing certify
Stargirl
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The Dawes Act
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The National Highway Traffic Safety Administration said it opened an audit query to examine the process and technical data Tesla used to certify the Cybercab.
From Los Angeles Times ● Sep. 4, 2026
March 8: US regulators with the Federal Aviation Administration certify the 737 MAX 8, which takes its first commercial flight weeks later.
From Barron's ● Aug. 3, 2026
People can now certify their expertise with particular AI platforms and strategies through paid and free certification programs.
From MarketWatch ● Jul. 31, 2026
When a manufacturer applies to certify a charging cable, it must submit 50 samples for evaluation.
From The Wall Street Journal ● Jul. 13, 2026
Now he has a degree to certify his nosiness.
From "On the Come Up" by Angie Thomas
One risk is that the project is strangled by inflexibility in the Navy’s technical bureaucracy that certifies parts.
From The Wall Street Journal ● Oct. 7, 2026
Most other closed-loop systems ran at about 32C in 2024, according to the Uptime Institute, which certifies data centers.
From Barron's ● Sep. 7, 2026
Among other things, it certifies animal safety on farms as well as on movie sets.
From Los Angeles Times ● May 12, 2026
Each year, the US government formally certifies whether several countries are fully co-operating with US-led counternarcotic efforts, and those which are found to be wanting risk having their US funding cut.
From BBC ● Sep. 16, 2025
He certifies to Abe's proficiency and worth in glowing terms.
From Abraham Lincoln, Volume 1 (of 2) The True Story Of A Great Life by William H. Herndon
Content is based on proprietary data, news and certified sell-side research.
From The Wall Street Journal ● Oct. 15, 2026
But California regulators certified a union representing Uber and Lyft drivers last month, marking a milestone in a years-long fight by gig workers in the state.
From Los Angeles Times ● Oct. 13, 2026
With the help of a certified financial planner, you could stress test your retirement with a variety of options.
From MarketWatch ● Oct. 8, 2026
Ozuna said that her daughter, the kindergarten teacher, holds a college degree and is working toward becoming a certified teacher but has struggled to get through a series of financial hoops.
From Salon ● Oct. 1, 2026
We could do whatever I wanted because I was a certified professional—it practically said so right there on my paycheck.
From "Me Talk Pretty One Day" by David Sedaris
Removing the pilot would have added the cost and complication of certifying a robot jet to fly fast over urban areas.
From BBC ● Sep. 24, 2026
EAC also oversees the federal testing and certification program for voting systems, accrediting labs and certifying whether machines meet federal standards known as the Voluntary Voting System Guidelines.
From Salon ● Jul. 11, 2026
The third-party certifying body administers random testing throughout the growing process and tests each product that arrives at the company’s New Jersey warehouse before it is released to stores, according to the website.
From Los Angeles Times ● May 12, 2026
The certifying official notes that the filer “will be in compliance” only “once the filer divests these assets.”
From MarketWatch ● May 7, 2026
Then a county judge issued a five-day restraining order forbidding the governor from certifying the result.
From "Votes for Women!" by Winifred Conkling
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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
