Expromissor
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
In the civil law. A person who assumes the debt of another, and becomes solely liable for it, by a stipulation with the creditor. He differs from a surety, inasmuch as this contract is one of novation, while a surety is jointly liable with hls principal.
Mackeld. Rom. Law, § 538.