A new lexicon emerges

Some words and phrases that became part of Americans' day-to-day vocabulary after Sept. 11:

Axis of Evil: Refers to Iran, Iraq and North Korea, according to President Bush, who accused those countries of supporting terrorism against other nations and trying to develop nuclear, chemical and biological weapons. Bush first used the phrase in his State of the Union address in January.

Dirty Bomb: A device to spread radioactive material, causing widespread fear. Consequences more psycho-social than medical. Not to be confused with a nuclear bomb, with its devastating fission explosion.

Ground Zero: Used to describe the World Trade Center site after the attacks. Originally a military term used to describe the point where a nuclear bomb explodes.

Homeland Defense: Defense of U.S. soil. Sept. 11 marked the first such serious concerns since Pearl Harbor.

-- Compiled from wire reports