surety
noun [ C or U ]
LAW uk/ˈʃɔːrəti/ us/ˈʃʊrətIi/ plural suretiesa person who accepts legal responsibility for another person's debt or behaviour:
act as surety for sb/sth He acted as surety for the two companies when they took out the original loan.
a promise, or money or property given as a promise, that someone will do something that they have said they will do, such as pay a debt or appear in court:
Analysts doubt whether Ford would have been able to raise such a large amount of debt without some kind of surety.
A local shopkeeper and a relative had been prepared to put up a surety of $20,000, the court heard.