/ʌnˈrɪtən lɔː/ – Phrase
Definition: luật không thành văn.
A more thorough explanation: Unwritten law refers to legal principles and rules that are not formally enacted by a legislative body but are based on custom, tradition, judicial decisions, and other sources of law that have evolved over time. These principles are not written in statutes or codes but are recognized and enforced by the legal system as part of the common law tradition.
Example: In this jurisdiction, the unwritten law regarding property rights is based on longstanding customs and traditions.