Cold War

The period between about 1945 and 1990 when the U.S. and the USSR wanted to go to war with each other but didn't. Instead they encouraged other, smaller countries to fight while they watched from the sidelines.

Berlin Wall

A big, concrete barrier topped with barbed wire surrounding a section of the German city of Berlin. It was erected by the communist east to keep their citizens from fleeing to the west.

Communism

An economic theory where all wealth is shared among the people, creating a utopia where government is unnecessary. This has never actually worked, but has often resulted in dictatorial rule and a disregard for human rights.

West Berlin

The capitalist, democratic side of Berlin where they painted the wall with awesome graffiti and where most people in communist East Berlin wished they could live.

Federal Republic

Also known as West Germany. The capitalist, democratic side that included West Berlin and was friendly with the United States.

Chancellor

Fancy word for the leader of Germany, similar to a president or a prime minister.

Civis Romanus sum

Latin for "I am a Roman citizen." Used as a really obnoxious way of demanding justice in ancient Rome.

Ich bin ein Berliner

German for "I too am a citizen of Berlin" (or "I am a jelly donut," depending on context and location). For more information about gooey German pastries and sticky urban legends check out this link.

Lass' sic nach Berlin kommen

German for "Let them come to Berlin" because it's totally cool to invite people over when you don't actually live there.

Eighteen years

The time that had passed between the time that World War II ended and when JFK gave his speech. Obviously, that number is way out of date today.

World War II

Every time Kennedy says "eighteen years," what he means is that it had been eighteen years since the end of World War II.