phosphorous

adjective

phos·pho·rous ˈfäs-f(ə-)rəs

fäs-ˈfȯr-əs

: of, relating to, or containing phosphorus especially with a valence lower than in phosphoric compounds

Word History

First Known Use

1788, in the meaning defined above

Time Traveler

The first known use of phosphorous was in 1788

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Cite this Entry

Style

“Phosphorous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phosphorous. Accessed 31 Oct. 2025.

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Medical Definition

phosphorous

adjective

phos·pho·rous ˈfäs-f(ə-)rəs; fäs-ˈfōr-əs

-ˈfȯr-

: of, relating to, or containing phosphorus especially with a valence lower than in phosphoric compounds

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