Indian Contract Act, 1872
126. "Contract of guarantee", "surety", "principal debtor" and "creditor"
A "contract of guarantee" is a contract to perform the promise, or discharge the liability, of a third person in case of his default. The person who gives the guarantee is called the "surety", the person in respect of whose default the guarantee is given is called the "principal debtor", and the person to whom the guarantee is given is called the "creditor". A guarantee may be either oral or written.