tu·​mor | \ ˈtü-mər How to pronounce tumor (audio) , ˈtyü-\

Definition of tumor

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

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Other Words from tumor

tumoral \ ˈtü-​mə-​rəl How to pronounce tumoral (audio) , ˈtyü-​ \ adjective
tumorlike \ ˈtü-​mər-​ˌlīk How to pronounce tumorlike (audio) , ˈtyü-​ \ adjective

Examples of tumor in a Sentence

the scan showed a small tumor in her abdomen
Recent Examples on the Web The debilitating pain that followed in Brown’s knee ultimately led to the discovery of a tumor in his left femur and the diagnosis of osteosarcoma, a rare form of bone cancer that typically is found in people under the age of 25. Beth Ann Nichols, The Courier-Journal, "Kentucky golfer Cullan Brown is fighting bone cancer, and joy is his 'secret weapon'," 10 Sep. 2019 Beagles can sniff out cancerous tumors in humans and let doctors know, for example, and a border collie can herd hundreds of sheep (or even turkeys) into an enclosure with remarkable speed and agility. Eva Frederick, Science | AAAS, "Humans haven’t just changed what dogs look like—we’ve altered the very structure of their brains," 2 Sep. 2019 Although surgery is typically the preferred treatment for a tumor in the pancreas, Ginsburg appears to have chosen radiation, which is generally less disruptive. Adam Liptak, BostonGlobe.com, "Ginsburg resumes a hectic schedule: ‘I am on my way to being very well’," 1 Sep. 2019 The discovery was a cancerous tumor in his appendix. Kellen Becoats, SI.com, "As the Storm Ready for the Playoffs, Coach Dan Hughes Reflects on His Fight with Cancer," 30 Aug. 2019 Anderson said she was recently told that the tumors in her brain, spine and lungs had stopped responding to treatment, leaving her with six to 12 months to live. Fox News, "Terminally ill nurse gets bucket list wish: a ride-along in a cop car," 27 Aug. 2019 Stroud is set to undergo a CT scan at Vanderbilt to look at the tumors in his lungs and determine the next course of action. Leada Gore | Lgore@al.com, al, "WAFF 48 reporter Allen Stroud updates progress in fight against stage 4 lung cancer," 21 Aug. 2019 After finding a tumor in his brain, doctors at Doernbecher Children’s Hospital were able to successfully remove it. Tim Brown, oregonlive.com, "Nike, Doernbecher reveal 6 patient-designers for 2019 DB Freestyle shoe, clothing collections," 12 Aug. 2019 In 2003, he was diagnosed with benign tumors in his spinal column. Jason Williams, Cincinnati.com, "PX column: As 2020 approaches, popular Hamilton County Commissioner Todd Portune's political future in limbo," 11 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tumor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of tumor

15th century, in the meaning defined at sense 2

History and Etymology for tumor

Middle English tumour, from Latin tumor, from tumēre

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Statistics for tumor

Last Updated

25 Oct 2019

Time Traveler for tumor

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

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More Definitions for tumor


How to pronounce tumor (audio)

English Language Learners Definition of tumor

: a mass of tissue found in or on the body that is made up of abnormal cells


tu·​mor | \ ˈtü-mər How to pronounce tumor (audio) , ˈtyü-\

Kids Definition of tumor

: an abnormal growth of body tissue


variants: or chiefly British tumour \ ˈt(y)ü-​mər How to pronounce tumour (audio) \

Medical Definition of tumor

: 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

Other Words from tumor

tumorlike \ -​ˌlīk How to pronounce tumorlike (audio) \ adjective

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More from Merriam-Webster on tumor

Thesaurus: All synonyms and antonyms for tumor

Rhyming Dictionary: Words that rhyme with tumor

Spanish Central: Translation of tumor

Nglish: Translation of tumor for Spanish Speakers

Britannica English: Translation of tumor for Arabic Speakers

Britannica.com: Encyclopedia article about tumor

Comments on tumor

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concealed or difficult to comprehend

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