Pronunciation: (bas'chun, -tē-un), [key]
1. Fort.a projecting portion of a rampart or fortification that forms an irregular pentagon attached at the base to the main work.
2. a fortified place.
3. anything seen as preserving or protecting some quality, condition, etc.: a bastion of solitude; a bastion of democracy.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.