to the greatest degree or extent or most advanced stage (`furthest' is used more often than `farthest' in this abstract sense); "went the furthest of all the children in her education"; "furthest removed from reality"; "she goes farthest in helping us"
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