Surety

The state of being sure; certainty; security.

That which makes sure; that which confirms; ground of confidence or security.

Security against loss or damage; security for payment, or for the performance of some act.

One who is bound with and for another who is primarily liable, and who is called the principal; one who engages to answer for another's appearance in court, or for his payment of a debt, or for performance of some act; a bondsman; a bail.

Hence, a substitute; a hostage.

Evidence; confirmation; warrant.

To act as surety for.

something clearly established