The definition of a tutor is a personal teacher, a teaching assistant or someone who helps a student catch up in a subject. An example of a tutor is someone who teaches a teenage celebrity. An example of a tutor is a teacher who assists a college professor with their teaching duties.
iron curtain-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.
Note: The expression Iron Curtain was coined by Winston Churchill, who was prime minister of Britain in World War II. Churchill first used the term soon after the war, when the Soviet Union was beginning to carry out its plans for postwar dominance of eastern Europe.