guarantee

From Wiktionary

guarantee is on the Academic Word List.

Noun

(countable) A guarantee is a formal promise that a product will be fixed or replaced or money will be repaid if it breaks or doesn't work.
The phone is covered by a six-month guarantee on parts and labour.
(countable) A guarantee is a formal promise that something will happen or be done.
The builders will now give performance and completion guarantees and will cover the costs of any problems.

Constitutional guarantees of freedom of speech are common in democracies.

The plan only operates for five years, with no guarantee of continuation.

Plain form
guarantee

Third-person singular
guarantees

Past tense
guaranteed

Past participle
guaranteed

Present participle
guaranteeing

(transitive) If you guarantee something, you promise to fixed or replace it or repay money if it breaks or doesn't work.
All of our products are guaranteed against defects in materials and workmanship for 3yrs from date of purchase.
(transitive) If you guarantee something, you make a formal promise that something will happen or be done.
the European Convention on Human Rights, guarantees the right to give and receive information.

When you put your money with us, your savings are 100% guaranteed.

The Americans said they could not guarantee his safety in Iraqi airspace.

If you go fishing with me, you're almost guaranteed success.