The software comes with a 'money-back guarantee'. [=a promise that the money you spend on a product will be returned if the product is not good enough]
We used our house as a 'guarantee' for the loan. [=we said that the bank could take our house if we did not pay back the loan]
There is no 'guarantee' that they will approve the contract. [=there is no way to be sure that they will approve it]
(..) one day in the navy. Holmes, are you sure that there is no alternative means of water transportaion, than that. I guarantee you nobody knows London's waterways better. Tanners practically a fish himself. At least he certainly drinks like one. Oh you've found your sense of humour, doctor. (..)2009 Sherlock Holmes