Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
designating or of chemical compounds in which osmium has a lower valence than in the corresponding osmic compounds
Used by arrangement with John Wiley & Sons, Inc.
The 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.
Of, relating to, or containing osmium in a compound with a valence lower than that in a comparable osmic compound.
Origin: osm(ium) + -ous.