Implies establishing authority or enforcing rules, often by a person in charge. Dad put his foot down about my bedtime; no more late nights.
Pro Tip 2/3
Not Aggressive
Though firm, it's not hostile or aggressive; it's more of a boundary-setting expression. The teacher put her foot down about cellphones in class, but she was still polite.
Pro Tip 3/3
Figurative Speech
This phrase is metaphorical and does not involve physical movement. When employees asked for less work, the boss put his foot down.