osmium tetroxide

noun Chemistry.
  1. a crystalline or amorphous, colorless, poisonous compound, OsO4, soluble in water, alcohol, and ether: used for microscopic staining, in photography, and as a catalyst in organic synthesis.

Origin of osmium tetroxide

First recorded in 1875–80
Also called osmic acid.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for osmic acid

osmium tetroxide

noun
  1. a yellowish poisonous water-soluble crystalline substance with a penetrating odour, used as a reagent and catalyst in organic synthesis. Formula: OsO 4
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

osmic acid in Medicine

osmic acid

[ŏzmĭk]
n.
  1. A crystalline oxide of osmium that is a volatile caustic and strong oxidizing agent, the aqueous solution of which is used as a stain for fat and myelin and as a general fixative for electron microscopy.
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