arsenious

adjective

ar·​se·​ni·​ous är-ˈsē-nē-əs How to pronounce arsenious (audio)
: of, relating to, or containing arsenic especially when trivalent

Word History

Etymology

borrowed from French arsénieux, from arsenic arsenic entry 1 + -ieux -ious

First Known Use

1796, in the meaning defined above

Time Traveler
The first known use of arsenious was in 1796

Rhymes for arsenious

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Browse Nearby Words

arseniosiderite
arsenious
arsenite
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Cite this Entry

“Arsenious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/arsenious. Accessed 8 Jul. 2026.

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Medical Definition

arsenious

adjective
ar·​se·​ni·​ous är-ˈsē-nē-əs How to pronounce arsenious (audio)
variants also arsenous
ˈärs-nəs, -ᵊn-əs How to pronounce arsenious (audio)
: of, relating to, or containing arsenic especially when trivalent
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