Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a black powder of finely divided metallic platinum, made by reduction of platinum salts: used as a catalyst, as in organic synthesis
Used by arrangement with John Wiley & Sons, Inc.
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A fine black powder of metallic platinum, used as a catalyst and as a gas absorbent.