1 a firm promise that sth will be done or that sth will happen 保证: The refugees are demanding guarantees about their safety before they return home. 难民要求有关方面在他们返国前保证他们的人身安全。

2 a written promise by a company that it will repair or replace a product if it breaks in a certain period of time 保证书 · The watch comes with a year's guarantee. 这块手表保修一年。Is the computer still under guarantee ? 这台计算机的保修期是不是还没有过？ ☞Look at warranty. 参看warranty。

3 something that makes sth else certain to happen 起保证作用的事物: Without a reservation there's no guarantee that you'll get a seat on the train. 不预订票的话，火车上不一定有座位。