To rule the roost means to be in charge; boss others.
To be the most powerful person in the group who makes all the decisions.
1. In our house, my parents rule the roost.
2. Joe is the boss at work but when he goes home, it’s his children that rule the roost.
3. My mother has always ruled the roost at home.
4. I love my job because I get to rule the roost.
control, crack the whip, dominate, govern, lead, manage, order, overrule, play fist fiddle, rule, take over, wear the pants