off–limits

off–limits /ˈɑːfˈlɪməts/ adjective
off–limits
/ˈɑːfˈlɪməts/
adjective
Britannica Dictionary definition of OFF–LIMITS
not used before a noun
1 
— used to say that people are not allowed to enter a place or use something
— often + to
2 
— used to say that people are not allowed to talk about something