1. a person who takes responsibility for another's performance of an undertaking, for example their appearing in court or the payment of a debt.Similarguarantorsponsor
▪ the state of being sure or certain of something:"I was enmeshed in the surety of my impending fatherhood"
Word OriginMiddle English (in the sense ‘something given to support an undertaking that someone will fulfill an obligation’): from Old French surte, from Latin securitas (see security).