One who becomes responsible for another. Christ is the surety of the better covenant (Hebrews 7:22). In him we have the assurance that all its provisions will be fully and faithfully carried out. Solomon warns against incautiously becoming security for another (Proverbs 6:1-5; 11:15; 17:18; 20:16).

Noah Webster's New International Dictionary of the English Language

1. (n.) A pledge, guarantee or security to insure a debt or obligation.

2. (n.) That which makes sure; that which confirms; ground of confidence or security.

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

4. (n.) 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.

5. (n.) Hence, a substitute; a hostage.

6. (n.) Evidence; confirmation; warrant.

7. (v. t.) To act as surety for.