untreated

adjective

un·​treat·​ed ˌən-ˈtrē-təd How to pronounce untreated (audio)
Synonyms of untreatednext
: not treated
untreated wastewater
especially : not improved or controlled medically
an untreated case of pneumonia
untreated diabetic patients

Synonyms of untreated

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Examples of untreated in a Sentence

untreated wool
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.
In some cases, water pressure drops, potentially allowing untreated groundwater to seep into pipes. — ABC News, 2 Aug. 2026 Since spring, some 10% of their research participants have been found to have active syphilis — cases that might otherwise have gone undiagnosed and untreated. — Eric Boodman, STAT, 31 July 2026 Tularemia, a bacterial disease, can become serious if left untreated. — Jennifer McLogan, CBS News, 31 July 2026 Migraines left untreated can progress into a chronic condition and can have a negative impact on one’s quality of life. — Helen Carefoot, Flow Space, 30 July 2026 See All Example Sentences for untreated

Word History

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of untreated was in the 15th century

Rhymes for untreated

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Browse Nearby Words

untreatable
untreated
untremulous
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Cite this Entry

“Untreated.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/untreated. Accessed 6 Aug. 2026.

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Medical Definition

untreated

adjective
un·​treat·​ed -ˈtrēt-əd How to pronounce untreated (audio)
: not subjected to treatment
an untreated disease

More from Merriam-Webster on untreated

Nglish: Translation of untreated for Spanish Speakers

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