Dictionary.com
Thesaurus.com
Synonyms

guarantee

American  
[gar-uhn-tee] / ˌgær ənˈti /

noun

guarantees plural
  1. a promise or assurance, especially one in writing, that something is of specified quality, content, benefit, etc., or that it will perform satisfactorily for a given length of time.

    a money-back guarantee.

  2. an assurance that another’s obligation will be fulfilled, or something presented as such security; guaranty.

  3. something that assures a particular outcome or condition.

    Wealth is no guarantee of happiness.

  4. a person who gives a guarantee or guaranty; guarantor.

  5. a person to whom a guarantee is made.


verb (used with object)

guarantees, present (3rd person singular) guaranteed, past participle, past guaranteeing present participle
  1. to secure, as by giving or taking security.

    A credit card guarantees your reservation at the hotel.

  2. to make oneself answerable for (something) on behalf of someone else who is primarily responsible.

    to guarantee the fulfillment of a contract.

  3. to undertake to ensure for another, as rights or possessions.

    The Constitution guarantees freedom of religion.

  4. to serve as a warrant or guaranty for.

  5. to undertake to protect or indemnify.

    to guarantee a person against loss.

  6. to undertake (to do something).

    I will guarantee to prove every word I stated.

  7. to promise (usually followed by a clause as object).

    I guarantee that I'll be there.

guarantee British  
/ ˌɡærənˈtiː /

noun

  1. a formal assurance, esp in writing, that a product, service, etc, will meet certain standards or specifications

  2. law a promise, esp a collateral agreement, to answer for the debt, default, or miscarriage of another

    1. a person, company, etc, to whom a guarantee is made

    2. a person, company, etc, who gives a guarantee

  3. a person who acts as a guarantor

  4. something that makes a specified condition or outcome certain

  5. a variant spelling of guaranty

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (also tr) to take responsibility for (someone else's debts, obligations, etc)

  2. to serve as a guarantee for

  3. to secure or furnish security for

    a small deposit will guarantee any dress

  4. to undertake to protect or keep secure, as against injury, loss, etc

  5. to ensure

    good planning will guarantee success

  6. (may take a clause as object or an infinitive) to promise or make certain

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does guarantee mean? A guarantee is a promise or assurance, especially one that is written or legally binding, that something is of a stated quality or will perform as stated, such as a guarantee that a car you purchase will operate correctly. A guarantee is also an assurance of a particular outcome or condition, as in Weather predictions are not guarantees. Weather often changes quickly. To guarantee something is to secure something, as a ticket guarantees entry to a movie showing. As well, to guarantee is to promise to do something, usually by signing a legally binding agreement, as in The company guaranteed me a job when I signed the contract. Example: I guarantee you will love your purchase and will give you a full refund if you don’t.

Other Word Forms

Derived Forms

Inflected Forms

Nouns

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of guarantee

First recorded in 1670–80; alteration of guaranty

Explanation

To guarantee is to promise or to a make binding agreement. If a baseball player guarantees his team will win the World Series, he better not lead the league in strikeouts. Guarantee is a word that is both a noun and a verb: the noun means "a binding agreement" and the verb is the act of making that agreement. This word seems to have come from garante, the Spanish word for "protect" and it's related to the Old French word warrant, which means "to authorize." Today, we often come across guarantee in advertisements, and you might wonder how they might guarantee to make your social life better if your teeth are whiter!

Keep Reading on Vocabulary.com

Vocabulary lists containing guarantee

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:

"That does not guarantee an uninterrupted move higher, but it gives the rebound a more credible foundation than short covering alone."

From Barron's Aug. 4, 2026

“A diplomatic process can reduce tail risk quickly, but it does not guarantee supply normalization on the same timetable.”

From MarketWatch Aug. 3, 2026

The deeper lesson, though, is that a constitutional right’s popular origins do not guarantee a democratic afterlife.

From Slate Aug. 3, 2026

“He’s an amazing player,” Suter said, “but it doesn’t mean a guaranteed World Series. It doesn’t guarantee anything.”

From Los Angeles Times Aug. 2, 2026

“I love it. And I can guarantee there’s not another blog out there like it.”

From "Insignificant Events in the Life of a Cactus" by Dusti Bowling

Recent history also suggests changing manager offers no guarantees.

From BBC Aug. 4, 2026

"I don't think one can give any guarantees," Raghu Iyer - chief executive of the Indian Olympic Association - told BBC Sport.

From BBC Aug. 2, 2026

Their scrappy determination helped convince family members, neighbors and eventually the rest of the country that the Constitution’s guarantees of liberty and equality applied to same-sex couples.

From Slate Aug. 1, 2026

“There should be some guarantees of enough water for a smaller farm,” said Judith Redmond, a Yolo County farmer who co-authored the report.

From Los Angeles Times Jul. 31, 2026

None of this would be easy or comfortable if it came to it, and there were, of course, no guarantees that any of us would survive.

From "Becoming" by Michelle Obama

One department where at least one more signing is guaranteed is up front, with PSG'S Bradley Barcola now Liverpool's primary target after they missed out on Yan Diomande.

From BBC Aug. 3, 2026

But the moment also made him reflect on the days, not long ago, when success hardly seemed guaranteed.

From Los Angeles Times Aug. 3, 2026

Their algorithm, called 'geographically ranked guaranteed proportionality', is designed to work around some of the limitations built into existing electoral systems.

From Science Daily Aug. 2, 2026

The effect, the author suggests, was lasting and unexpectedly salutary, with the new emperor’s detachment strengthening Rome’s “emergent bureaucracy,” made up of administrators whose “whose self-interest guaranteed orderly solutions to local problems.”

From The Wall Street Journal Jul. 31, 2026

Anybody who wanted to play could sign up and they were guaranteed at least a quarter of playing time.

From "We Were Here" by Matt De La Peña

Activists say they applaud foreign exhibitions of heritage treasures — as long as laws guaranteeing their return are followed.

From Los Angeles Times Jul. 14, 2026

Micron secured 16 long-term supply deals, guaranteeing approximately $100 billion in revenue and ensuring gross margins well above past peaks.

From Barron's Jun. 25, 2026

Success at Harlequins six days after that debacle was Sale's only away victory in The Prem and gave them some breathing space in guaranteeing a top-eight spot and a Champions Cup place for next season.

From BBC Jun. 10, 2026

Meta Platforms is launching a free, five-week “workforce academy” to train Americans to build its data centers, guaranteeing graduates a job.

From The Wall Street Journal Jun. 8, 2026

If we could check that the candidate landing site was not covered with sifting, drifting dust, we would have at least a fair chance of guaranteeing that the winds were not intolerably high.

From "Cosmos" by Carl Sagan

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training