noun · 3 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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ŏz'mēəm
UK:/ˈɒz.mi.əm/
Southern-England:Recorded audio is listed in the source snapshot.
US:/ˈɑz.mi.əm/
General-American:Recorded audio is listed in the source snapshot.
CMU ARPABET:AA1 Z M IY0 AH0 M
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
A chemical element (symbol Os) with atomic number 76: a hard, brittle, heavy, bluish-white transition metal found as a trace element in alloys, mostly in platinum ores.
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
Examples
Their latest catalyst includes some osmium.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
noun
Meaning 2
A single atom of this element.
Definition source: English Wiktionary via Wiktextract
Usage: countable
Examples
This reaction substitutes a ruthenium for an osmium.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
noun
Meaning 3
a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: Os, atomic number 76
Antonyms: none provided
Broader terms: metallic element, metal
History
Etymology
From Ancient Greek ὀσμή (osmḗ, “smell”) (because of the strong smell of its oxide) + -ium.
Across languages
Translations
76 source translations are retained for this English entry.
