bullet train

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A high-speed passenger train.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun rail transport The shinkansen, a high-speed passenger train of Japan. Runs at speeds from 200-300 kilometers per hour.
• noun informal Suicide by small firearm; see take the bullet train.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a high-speed passenger train