guarantee

UK: /ˌgærənˈtiː/ US: /ˌgærənˈti/ ,(gar′ən tē′)

Inflections of 'guarantee' (v): (⇒ conjugate)

guarantees

v 3rd person singular

guaranteeing

v pres p

guaranteed

v past

guaranteed

v past p

WordReference Random House Learner's Dictionary of American English © 2026

guar•an•tee /ˌgærənˈti/   n., pl. -tees, v., -teed, -tee•ing. 
n. [countable]

1. an assurance, esp. one in writing, that something is of specified quality, content, benefit, etc., or will please the customer or perform satisfactorily for a given length of time.
2. guaranty (defs. 1, 2).
3. something that makes sure a particular outcome or condition will come to pass:
   Wealth is not a guarantee of happiness.

v. 

4. to offer a guarantee for:
   [~ + object] The company guarantees its machines for ten years.
5. to make oneself answerable for (something) on behalf of someone else;
   vouch for:
   [~ + object] I guarantee his behavior.
6. to protect against damage or loss:
   [~ + object] This insurance guarantees a person against property loss.
7. to assure that a stated outcome is certain: [~ + object + to + verb]
   That clown show is guaranteed to bring a smile to your face.
   [~ + (that) clause]
   I guarantee that I'll be there.

WordReference Random House Unabridged Dictionary of American English © 2026

guar•an•tee  (gar′ən tē′), n., v., -teed, -tee•ing. 
n. 

1. a promise or assurance, esp. 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. guaranty (defs. 1, 2).
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.

v.t. 

6. to secure, as by giving or taking security.
7. to make oneself answerable for (something) on behalf of someone else who is primarily responsible:
   to guarantee the fulfillment of a contract.
8. to undertake to ensure for another, as rights or possessions.
9. to serve as a warrant or guaranty for.
10. to engage to protect or indemnify:
    to guarantee a person against loss.
11. to engage (to do something).
12. to promise (usually fol. by a clause as object):
    I guarantee that I'll be there.

• alteration of guaranty 1670–80

Collins Concise English Dictionary © HarperCollins Publishers::

guarantee / ˌɡærənˈtiː/ noun

1. a formal assurance, esp in writing, that a product, service, etc, will meet certain standards or specifications
2. a promise, esp a collateral agreement, to answer for the debt, default, or miscarriage of another
3. a person, company, etc, to whom a guarantee is made
4. a person, company, etc, who gives a guarantee
5. a person who acts as a guarantor
6. something that makes a specified condition or outcome certain
7. a variant spelling of guaranty

verb ( -tees, -teeing, -teed)(mainly tr)

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. usually followed by from or against: 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

Etymology: 17th Century: perhaps from Spanish garante or French garant, of Germanic origin; compare warrant