/kəʊ-ˈprɒmɪsə/ – noun
Definition: đồng con nợ.
A more thorough explanation: A co-promisor is a person who, along with one or more other individuals, agrees to be equally responsible for the same debt or obligation under a contract or agreement.
Example: In the contract, John acted as a co-promisor, jointly promising to fulfill the obligations alongside the main promisor.