di·phos·gene (dī-fŏz'jēn')
n.
A colorless liquid, ClCO₂CCl₃, used in organic synthesis. Its vapor was used as a poison gas in World War I.

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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