os·​mi·​um | \ ˈäz-mē-əm How to pronounce osmium (audio) \

Definition of osmium

: a blue-gray or blue-black hard brittle very heavy polyvalent metallic element with a high melting point that is used especially as a catalyst and in hard alloys — see Chemical Elements Table

Examples of osmium in a Sentence

Recent Examples on the Web Because of its durability, osmium is used in electronics, as well, to make record player needles and fountain pens. Caroline Delbert, Popular Mechanics, 25 Apr. 2022 While brilliant, Kolnai’s writing has the density of osmium. New York Times, 27 Dec. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'osmium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of osmium

1804, in the meaning defined above

History and Etymology for osmium

Greek osmḗ "smell, odor" + -ium; osmḗ going back to *od-s-mā, noun derivative from the base of ózein "to smell, give off an odor" — more at odor

Note: The word osmium was introduced by the English chemist Smithson Tennant (1761-1815) in Philosophical Transactions of the Royal Society, 1804, Part II, p. 416: "When the alkaline solution [obtained by dissolving impure platinum] is first formed, by adding water to the dry alkaline mass in the crucible, a pungent and peculiar smell is immediately perceived. This smell, as I afterwards discovered, arises from the extrication of a very volatile metallic oxide; and, as this smell is one of its most distinguishing characters, I should on that account incline to call the metal Osmium." In the same report Tennant discussed and named the element iridium (see iridium).

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Dictionary Entries Near osmium



osmium dioxide

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Statistics for osmium

Last Updated

4 May 2022

Cite this Entry

“Osmium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/osmium. Accessed 19 May. 2022.

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More Definitions for osmium


os·​mi·​um | \ ˈäz-mē-əm How to pronounce osmium (audio) \

Medical Definition of osmium

: a hard brittle blue-gray or blue-black polyvalent metallic element of the platinum group with a high melting point that is the heaviest metal known and that is used especially as a catalyst and in hard alloys symbol Os — see Chemical Elements Table

More from Merriam-Webster on osmium

Britannica.com: Encyclopedia article about osmium


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