rule the roost

US /ruːl ðə ruːst/
UK /ruːl ðə ruːst/
"rule the roost" picture
1.

当家作主, 掌权

to be in charge, to be the dominant person or group in a situation

:
In their household, it's clear that the grandmother rules the roost.
在他们家里,很明显是奶奶当家作主
The new manager quickly established himself and now rules the roost in the department.
新经理很快站稳了脚跟,现在在部门里当家作主