sponsion
noun
spon·sion
ˈspänchən
plural -s
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
Word History
Etymology
Latin sponsion-, sponsio, literally, solemn promise, pledge, from sponsus (past participle of spondēre to promise solemnly) + -ion-, -io -ion