FIDE-JUSSOR
FIDE-JUSSOR, civil law. One who becomes security for the debt of another, promising to pay it in case the principal does not do so.
2. He differs from co-obligor in this, that the latter is equally bound to a debtor with his principal, while the former is not liable till the principal has failed to fulfil his engagement. Dig. 12, 4, 4; Id. 16, 1, 13; Id. 24, 3, 64; Id. 38, 1, 37; Id. 50, 17, 110, and 14, 6, 20; Hall's Pr. 33; Dunl. Ad. Pr. 300; Clerke's Prax. tit. 63, 4, 5.
3. The obligation of the fide-jussor was an accessory contract, for, if the principal obligation was not previously contracted, his engagement then took the name of mandate. Lec. Elem. §872; Code Nap. 2012.