/ˈkɒnswɪtjuːd/ – noun
Definition: phong tục, tập quán, tục lệ, luật không thành văn.
A more thorough explanation: Consuetude refers to a long-established custom or practice that has acquired the force of law through continuous and uniform usage.
Example: The court relied on the consuetude of the local community in interpreting the customary law.