Synonyms of guarantee

guarantee 1 of 2

verb

1

as in to bond

to assume responsibility for the satisfactory quality or performance of

the shop will guarantee all work done on the car for 30 days

Synonyms & Similar Words

• bond
• assure
• guaranty
• certify
• pledge
• warrant
• contract
• undertake
• insist
• insure
• testify (to)
• vow
• attest
• stipulate
• declare
• swear
• adhere
• assert
• witness
• vouch (for)
• authenticate
• plight
• aver
• covenant
• avouch
• avow

2

as in to ensure

to make sure, certain, or safe

I can guarantee that you'll feel better after using my product for 30 days

Synonyms & Similar Words

• ensure
• assure
• secure
• insure
• guaranty
• ice
• promise
• cinch
• vouch
• certify
• warrant
• pledge
• witness
• swear
• attest

Antonyms & Near Antonyms

• undermine
• weaken
• enfeeble

3

as in to declare

to state clearly and strongly

I guarantee that this movie is better than the last one in the series

Synonyms & Similar Words

• declare
• assert
• announce
• proclaim
• profess
• say
• affirm
• explain
• justify
• lay down
• aver
• assure
• promote
• defend
• advertise
• avow
• emphasize
• convince
• avouch
• pronounce
• uphold
• stress
• publicize
• advance
• boost
• advocate
• persuade
• accent
• underline
• plug
• support
• underscore
• accentuate
• call
• reaffirm
• rationalize
• reassert
• espouse
• blaze
• champion

Antonyms & Near Antonyms

• minimize
• ignore
• disregard
• understate
• neglect
• overlook

guarantee

2 of 2

noun

ˌger-ən-ˈtē 

1

as in contract

a formal agreement to fulfill an obligation

the contractors gave us a written guarantee that the work on the house would be done by Christmas

Synonyms & Similar Words

• contract
• deal
• vow
• guaranty
• pledge
• assurance
• warranty
• bond
• surety
• treaty
• covenant
• pact
• oath
• bargain
• deposit
• seal
• convention
• insurance
• security
• compact
• word
• accord
• concordat
• bail
• troth
• pawn

2

as in pledge

something given or held to assure that the giver will keep a promise

you'll have to give your car keys as a guarantee that you'll come back

Synonyms & Similar Words

• pledge
• security
• promise
• guaranty
• assurance
• gage
• deposit
• pawn
• bond
• bail
• warranty
• contract
• commitment
• down payment
• surety
• oath
• earnest
• covenant
• compact
• word
• recognizance
• handsel
• troth

Example Sentences

Recent Examples of guarantee

Verb

Both movies are all but guaranteed to cross the billion-dollar mark next week. — Bethy Squires, Vulture, 2 Aug. 2026

If the Republican brand is toxic enough to guarantee a mathematical ceiling, the only viable path to the governor’s mansion may require shedding the partisan skin entirely. — Dain Fitzgerald, The Washington Examiner, 1 Aug. 2026

Noun

Haile, the screenings at Berlin were so well attended, which isn’t a guarantee for everything at the festival. — Zac Ntim, Deadline, 2 Aug. 2026

The search fund model — popularized at Stanford and Harvard — lets MBAs eventually own 20%–25% of a business, with institutional equity and no personal guarantee on the debt. — Nick Lichtenberg, Fortune, 2 Aug. 2026