open secret
US /ˈoʊpən ˈsiːkrət/
UK /ˈoʊpən ˈsiːkrət/

1.
rahsia umum
a fact that is supposed to be secret but is actually known by many people
:
•
It's an open secret that they are planning to get married.
Ia adalah rahsia umum bahawa mereka merancang untuk berkahwin.
•
His affair with his assistant was an open secret in the office.
Hubungan sulitnya dengan pembantunya adalah rahsia umum di pejabat.