tumor

noun

tu·​mor ˈtü-mər How to pronounce tumor (audio)
ˈtyü-
1
: an abnormal benign or malignant new growth of tissue that possesses no physiological function and arises from uncontrolled usually rapid cellular proliferation

called also neoplasm

2
: a swollen or distended part
… houses that bulged with the tumors and warts of … ornamental architecture …W. A. White
tumoral adjective
tumorlike adjective

Examples of tumor in a Sentence

the scan showed a small tumor in her abdomen
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.
Complications also arose for Alexis just a few years after her tumor was removed when her leg was amputated after her internal prosthetic leg failed. Julie Gallant, San Diego Union-Tribune, 19 Aug. 2025 For patients under 19, these same medications can be prescribed for other medical reasons, such as post-chemotherapy needs, tumor removal surgery or to treat precocious puberty (when a child goes through puberty too early). Charlotte Observer, 13 Aug. 2025 The grape-sized, Stage 4 tumor on his brain stem made his movements and memories shaky. Yuki Noguchi, NPR, 13 Aug. 2025 And the result is more tumors are being caught in the early stages when the chances of survival are much higher — around 91%. Lisa Jarvis, Twin Cities, 12 Aug. 2025 See All Example Sentences for tumor

Word History

Etymology

Middle English tumour, from Latin tumor, from tumēre

First Known Use

15th century, in the meaning defined at sense 2

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

Browse Nearby Words

Cite this Entry

“Tumor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tumor. Accessed 24 Aug. 2025.

Kids Definition

tumor

noun
tu·​mor ˈt(y)ü-mər How to pronounce tumor (audio)
: an abnormal mass of tissue that arises from normal tissue cells and serves no useful purpose in the body
tumorous
ˈt(y)üm-(ə-)rəs
adjective

Medical Definition

tumor

noun
tu·​mor
variants or chiefly British tumour
: an abnormal benign or malignant new growth of tissue that possesses no physiological function and arises from uncontrolled usually rapid cellular proliferation see cancer sense 1, carcinoma, sarcoma
tumorlike adjective

More from Merriam-Webster on tumor

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