osmium tetroxide
noun
: a crystalline compound OsO4 that is an oxide of osmium, has a poisonous irritating vapor, and is used as a catalyst, oxidizing agent, and biological fixative and stain
Word History
First Known Use
1869, in the meaning defined above
Medical Definition
osmium tetroxide
noun
: a crystalline compound OsO4 that is an oxide of osmium, has a poisonous irritating vapor, and is used chiefly as a catalyst, as an oxidizing and hydroxylating agent (as in the conversion of alkenes to glycols), and as a biological fixative and stain (as for fatty substances in cytology)
called also osmic acid