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1. A projecting part of a fortification.
2. A well-fortified position.
3. One that upholds or defends something, as against neglect or unpopularity: a college that is a bastion of traditionalism. See Synonyms at bulwark.
[French, from Old French bastillon, from bastille, fortress; see bastille.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.