To give an assurance that something will be done right.
To assume or take responsibility for a debt or other obligation.
To make something certain.
The long sunny days guarantee a good crop.
An undertaking to answer for the payment of some debt, or the performance of some contract or duty, of another, in case of the failure of such other to pay or perform; a warranty; a security.
Something serving as a security for such an undertaking.
An assurance or guarantee.