Hush up and Iron curtain

Hush up verb - To keep from being publicly known.

Iron curtain and hush up are semantically related In some cases you can use "Iron curtain" instead a noun "Hush up".

Iron curtain noun - An impenetrable barrier to communication or information especially as imposed by rigid censorship and secrecy; used by Winston Churchill in 1946 to describe the demarcation between democratic and communist countries.

Hush up and iron curtain are semantically related in forbiddance topic. Sometimes you can use "Hush up" instead a noun phrase "Iron curtain".