To take a decided stand; be stubborn in decision.
Занять твeрдую позицию; быть непреклонным в своем решении.
John didn't want to practice his piano lesson, but his teacher put his foot down.
This has gone far enough; he is going to put his foot down.
Это зашло довольно далеко; он собирается положить этому конец.
When it came to smoking pot at parties, our parents put their foot down.