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
an embankment built around a space for defensive purposes; "they stormed the ramparts of the city"; "they blew the trumpet and the walls came tumbling down"
a telecommunication system that transmits images of objects (stationary or moving) between distant points
broadcasting visual images of stationary or moving objects; "she is a star of screen and video"; "Television is a medium because it is neither rare nor well done" - Ernie Kovacs