I.a solemn promise or engagement to some performance (in bargains, covenants, treaties, etc.); a promise, guarantee, security, sponsion for any one (freq. and class.; cf.: pactio, foedus).
I. In gen.: “sponsio appellatur omnis stipulatio promissioque,” Dig. 50, 16, 7: “voti sponsio, quā obligamur deo,” Cic. Leg. 2, 16, 41: “Scandilium cogis sponsionem acceptam facere,” Cic. Verr. 2, 3, 60, § 139: “per inducias sponsionem faciunt, uti, etc.,” made an agreement, Sall. J. 79, 4: “non foedere pax Caudina sed per sponsionem facta est,” by giving surety, Liv. 9, 5, 2: “sponsione se obstringere,” id. 9, 8, 4: “sponsionem interponere,” id. 9, 9, 4; and: “tunc sponsio et pax repudietur ... nec populus Romanus consulum sponsionem nec nos fidem populi Romani accusemus,” id. 9, 11, 5: “Ocriculani sponsione in amicitiam accepti,” id. 9, 41, 20; 39, 43, 5 (but Plaut. Trin. 2, 4, 26, is spurious; v. Ritschl ad h. l.).—
II. In partic., in civil suits, a mutual agreement or stipulation of the parties, that he who loses should pay a certain sum to him who gains the cause, a sort of wager at law: per sponsionem hoc modo agimus; “provocamus adversarium tali sponsione: si homo quo de agitur ex jure Quiritium meus est, sestertios XXV. nummos dare spondes?” Gai. Inst. 4, 93: “condicio Quintio fertur, ut, si id factum negaret ceteraque, quae objecisset, sponsione defenderet sese,” Liv. 39, 43, 5: “in probrum suum sponsionem factam,” id. 40, 46, 14; hence, sponsio (sponsionem facere) si non (ni), a wager that, to agree to make a payment if not: “ut sponsionem facere possent, ni adversus edictum praetoris vis facta esset,” Cic. Caecin. 16, 45: “sponsio est, ni te Apronius socium in decumis esse dicat,” Cic. Verr. 2, 3, 59, § 135: “sponsionem milium nummūm facere cum lictore suo, ni furtis quaestum faceret,” id. ib. 2, 5, 54, § 131; cf.: “jubet Quinctium sponsionem cum Sex. Naevio facere, si bona sua ex edicto dies XXX. possessa non essent,” id. Quint. 8, 30; id. Fam. 7, 21 init.; id. Pis. 23, 55: “sponsione optime facere posse,” id. Caecin. 16, 45; id. Off. 3, 19, 77: “Apronium sponsione lacessivit,” Cic. Verr. 2, 3, 57, § 132: “sponsione vincere,” id. Quint. 27, 84.—Post-class., with quod: “de sponsione quam is cum adversario, quod vir bonus esset, fecerat,” Val. Max. 7, 2, 4: “sponsionem provocare, quod, etc.,” id. 2, 8, 2; 6, 1, 10.—With acc. and inf.: “Cleopatra sponsione revocavit, insumere se posse, etc.,” Macr. S. 2, 13.—
2. Hence, in gen., a bet, betting: “audax,” Juv. 11, 202.—
B. Meton., a sum of money deposited according to agreement, a stake, acc. to Varr L. L. 6, § 70 Müll.