Dead air and Iron curtain

Dead air noun - An inadvertent interruption in a broadcast during which there is no sound.

Iron curtain and dead air are semantically related in speech topic. In some cases you can use "Iron curtain" instead a noun phrase "Dead air", when it comes to topics like silence.

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.

Dead air and iron curtain are semantically related in speech topic. You can use "Dead air" instead a noun phrase "Iron curtain", if it concerns topics such as silence.