householdlaw

noun
UK /ˈhaʊshəʊld lɔː/
US /ˈhaʊshoʊld lɔː/

A rule that everyone in a home must follow.

Cleaning your room before dinner is a household law in our family.


OTHER MEANINGS

2. The set of rules a family agrees on to keep the home running smoothly.

The household law says lights go out at nine o'clock.

3. A rule about how shared spaces and items at home are used.

By household law, whoever uses the last of the milk buys more.

4. An informal custom that everyone at home treats as required.

Taking off your shoes at the door became a household law years ago.