noun
unwritten law; common law
Legal term for law based on custom or precedent rather than written statutes. Contrasts with 成文律 (written law).
See also: 成文律
イギリスでは不文律が重要な役割を果たしている。
In England, unwritten law plays an important role.
noun
unwritten rule; tacit understanding
Commonly used for social norms, customs, or implicit agreements that are not formally written down.
職場には、残業は断らないという不文律がある。
There is an unwritten rule at the workplace that you don't refuse overtime.