osmium

noun

os·​mi·​um ˈäz-mē-əm How to pronounce osmium (audio)
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
While zircons from this time period have not yet been studied, Halverson notes that previous studies of snowball Earth have tracked the presence of iron, neodymium, and osmium in the geologic record. — Ars Technica, 28 Feb. 2025 Both elements belong to the same group of periodic metals known as platinum group metals (PGMs), which also includes ruthenium, rhodium, osmium and iridium. — Victor Rosario, Sacramento Bee, 26 Feb. 2025

Word History

Etymology

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).

First Known Use

1804, in the meaning defined above

Time Traveler
The first known use of osmium was in 1804

Phrases Containing osmium

Browse Nearby Words

osmiridium
osmium
osmium dioxide
See all Nearby Words

Cite this Entry

“Osmium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/osmium. Accessed 21 Apr. 2025.

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Kids Definition

osmium

noun
os·​mi·​um ˈäz-mē-əm How to pronounce osmium (audio)
: a hard brittle blue-gray or blue-black metallic element with a high melting point that is the heaviest metal known see element

Medical Definition

osmium

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

Last Updated: - Updated example sentences
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