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.
Instead of waiting for tumors to grow, doctors could use routine blood monitoring to guide treatment changes earlier, extending the time patients live without their disease advancing. Lauryn Higgins, Flow Space, 21 Oct. 2025 Initially, it was believed Carter had a stage 1 or 2 Wilms tumor, also known as nephroblastoma, the most common and treatable kidney cancer. Tereza Shkurtaj, PEOPLE, 19 Oct. 2025 Treatments for Potentially Resectable Stomach Cancer People with potentially resectable stomach cancer have a cancerous tumor that has grown into more layers of the stomach lining or wall. Carrie Madormo, Health, 18 Oct. 2025 The man placed his hand on Williams’ hip, right above his tumor. Luca Evans, Denver Post, 17 Oct. 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 22 Oct. 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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