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]
(..) is surrounding this place. Ten hours of flight time is a week at this level. That means each and every one of us will be killed. That I can guarantee you. We have no other choice but to continue on and do it as fast as possible. Downwards is the only way forwards. Get ready. (..)2010 Inception
(..) his father's empire. - Cobb, we should walk away from this. - Hold on. If I were to do this, if I even could do it... ... I would need a guarantee. - How do I know you can deliver? - You don't. But I can. So do you want to take a leap of faith... ...or become an old man, (..)2010 Inception