noun保证,担保;保证书,保修单
verb保证,担保;提供保修
nouna promise that something will happen
nouna written promise by a company that it will repair a thing you have bought, or give you a new one, if it goes wrong
verbto promise that something will be done or will happen
verbto say that you will repair a thing that somebody buys, or give them a new one, if it goes wrong