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
W. A. WhiteExamples of tumor in a Sentence
the scan showed a small tumor in her abdomen
Recent Examples on the Web
She was prescribed monthly drug injections and scans to monitor the tumors — but was told chemotherapy wouldn’t work.
—Cara Lynn Shultz, People.com, 26 Mar. 2025
The breast tumor is larger than 5 centimeters and has spread to one to three lymph nodes, or the tumor is any size and has spread to four to nine lymph nodes.
—Joy Emeh, Health, 25 Mar. 2025
After the tumor is surgically removed, patients typically receive BCG to help boost their immune system in eliminating any remaining cancer cells.
—Jenny Lehmann, Discover Magazine, 25 Mar. 2025
Love had been diagnosed with brain cancer and underwent immunotherapy as part of a clinical trial at Duke University’s brain tumor center, according to the Associated Press.
—Essence News Editors, Essence, 24 Mar. 2025
See All Example Sentences for tumor
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.
Cara Lynn Shultz, People.com, 26 Mar. 2025
The breast tumor is larger than 5 centimeters and has spread to one to three lymph nodes, or the tumor is any size and has spread to four to nine lymph nodes.
—Joy Emeh, Health, 25 Mar. 2025
After the tumor is surgically removed, patients typically receive BCG to help boost their immune system in eliminating any remaining cancer cells.
—Jenny Lehmann, Discover Magazine, 25 Mar. 2025
Love had been diagnosed with brain cancer and underwent immunotherapy as part of a clinical trial at Duke University’s brain tumor center, according to the Associated Press.
—Essence News Editors, Essence, 24 Mar. 2025
See All Example Sentences for tumor
Cite this Entry
“Tumor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tumor. Accessed 2 Apr. 2025.
Copy CitationKids Definition
tumor
noun
tu·mor
ˈt(y)ü-mər 
: an abnormal mass of tissue that arises from normal tissue cells and serves no useful purpose in the body
tumorous
adjective
ˈt(y)üm-(ə-)rəs
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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share