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

Relevance
See All Synonyms & Antonyms in Thesaurus

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.
But bleeding, lessons, and blockages can develop in the small intestine which can lead to big problems if left untreated. — Mack Degeurin, Popular Science, 29 Oct. 2026 When left untreated, gonorrhea can lead to pelvic inflammatory disease and infertility. — ABC News, 27 Oct. 2026 These symptoms, if left untreated, can be enormously challenging for women and their families. — Lyndon Haviland, Washington Post, 23 Oct. 2026 Squamous cell carcinoma is the second most common, but unlike basal cell, this skin cancer can spread if untreated. — Norah O'Donnell, CBS News, 21 Oct. 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

See All Rhymes for untreated

Browse Nearby Words

untreatable
untreated
untremulous
See all Nearby Words

Cite this Entry

“Untreated.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/untreated. Accessed 1 Nov. 2026.

Copy Citation

Medical Definition

untreated

adjective
un·​treat·​ed -ˈtrēt-əd How to pronounce untreated (audio)
: not subjected to treatment
an untreated disease
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of Pyrrhic

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Pwn, Skibidi, Girlboss and Other Words Added to the 2026 Scrabble Dictionary

The Words of the Week - Oct. 30

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
couple-laugh-cafe
Quiz: Foreign Phrases You Should Know Check out your bona fides and avoid any faux pas.
See All