ˈspänchən noun
( -s )
Etymology: Latin sponsion-, sponsio, literally, solemn promise, pledge, from sponsus (past participle of spondēre to promise solemnly) + -ion-, -io -ion — more at spouse
1. Roman law : suretyship accessory to oral contracts and available only to Roman citizens
2. : the act of becoming surety ; especially : a formal pledge made on behalf of another
3. : an act or engagement on behalf of a state undertaken by an agent not specially authorized or by one who exceeds the limits of his authority and requiring for validity ratification by the state