surety

nouns

something clearly established
is a type of (narrower)
something that is certain
"his victory is a certainty"
property that your creditor can claim in case you default on your obligation
"bankers are reluctant to lend without good security"
a prisoner who is held by one party to insure that another party will meet specified terms
one who provides a warrant or guarantee to another
a guarantee that an obligation will be met