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
-
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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
The Dawes Act
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
This Week In Words: November 28–December 4, 2020
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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:
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
Counties can ask for an extension, and they still have up to 30 days to certify the results, so the law only goes so far.
From Salon ● Jun. 9, 2026
Technically, local election officials have 30 days to process and certify all ballots, though it rarely takes that entire time to declare a winner.
From Los Angeles Times ● Jun. 2, 2026
“Well, then, it’s up to me to certify you, isn’t it?”
From "Challenger Deep" by Neal Shusterman
August 3: The FAA certifies the 737 MAX 7, Boeing's first new aircraft since the 2018 and 2019 crashes.
From Barron's ● Aug. 3, 2026
Denise Brown, whose Caregiving Years Training Academy certifies caregiving consultants, says Nonie’s monthlong stay demonstrated her desire to make sure her parents were all right.
From The Wall Street Journal ● Jul. 4, 2026
GKN Aerospace’s Garden Grove facility, which sits on 15.5 acres on Western Avenue, designs, analyzes, tests and certifies military canopies, cockpit windows and passenger widows, according to its website.
From Los Angeles Times ● May 23, 2026
An office that certifies schools whose students are eligible for financial aid?
From Slate ● Jul. 15, 2025
Saint-Simon, who cannot be suspected of hostility towards the nobility, certifies to this.
From Louis XIV and La Grande Mademoiselle 1652-1693 by Arvede Barine
“She told me she had completely cut off her mom,” says Sherlock, 29, a certified public accountant in Lakeville, Minn. “And that she had wasted all of her 30s on a man.”
From The Wall Street Journal ● Aug. 22, 2026
More and more people are taking a non-traditional retirement approach,” said Flavio Landivar, a certified financial planner at Evensky & Katz/Foldes Wealth Management.
From MarketWatch ● Aug. 21, 2026
So before you start, speak to a certified exercise physiologist or physiotherapist.
From Science Daily ● Aug. 16, 2026
The App Drivers Union was certified in May to represent roughly 70,000 Uber and Lyft drivers in that state.
From Los Angeles Times ● Aug. 15, 2026
To improve the Viking options, additional landing sites, geologically very different from Chryse and Cydonia, were selected in the radar- certified region near 4° S latitude.
From "Cosmos" by Carl Sagan
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
To gain entry to the program, firms must meet a slate of requirements, among them certifying a minimum number of people in a proctored exam and meeting Anthropic’s bar for “deploying Claude responsibly,” Kadon added.
From The Wall Street Journal ● Jun. 3, 2026
The certifying official notes that the filer “will be in compliance” only “once the filer divests these assets.”
From MarketWatch ● May 7, 2026
Vertical Aerospace is still certifying aircraft for commercial service and isn’t as well-known as some of the other players trying to create a “low altitude economy,” including Joby Aviation, Archer Aviation, and Beta Technologies.
From Barron's ● Mar. 26, 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
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
