can·​cer | \ˈkan(t)-sər \

Definition of cancer 

1 capitalized

a : a northern zodiacal constellation between Gemini and Leo

b(1) : the fourth sign of the zodiac in astrology — see Signs of the Zodiac Table

(2) : one born under the sign of Cancer I'm a Taurus, but my best friend is a Cancer.

2 [ Latin, crab, cancer ]

a : a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis

b : an abnormal bodily state marked by such tumors

3 : something evil or malignant that spreads destructively the cancer of hidden resentmentIrish Digest

4a : an enlarged tumorlike plant growth (such as that of crown gall)

b : a plant disease marked by such growths

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Other Words from cancer

cancerous \ ˈkan(t)s-​rəs , ˈkan(t)-​sə-​ \ adjective
cancerously adverb

Did You Know?

The Latin word cancer, meaning “crab,” was also given as a name to several diseases. One of the diseases was the abnormal, spreading mass of tissue we call a tumor. A possible explanation for this extended use of cancer is that the Romans thought some tumors looked like many-legged crabs. A French descendant of this Latin word was borrowed into English as canker. It is now applied to several plant and animal disorders. In the 14th century the Latin word cancer in the sense of “tumor” was borrowed directly into English, giving us our modern spelling and sense.

Examples of cancer in a Sentence

He was diagnosed with cancer. She learned that she has cancer. Eating certain foods may help reduce the risk of cancer. Advanced cancers are more difficult to treat. I'm a Taurus, but my best friend is a Cancer.
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Recent Examples on the Web

And his dislikes: Pants, dirty stupid cancer, and the times hospital workers had to access his medical port. Fox News, "Obit, memorial service of 5-year-old Iowa boy gets attention," 13 July 2018 Recently, researchers have used a smaller version of the scanner in studies of cancer, bone and joint health, with positive results. Jason Daley, Smithsonian, "Check Out These Awesome New 3D, Full-Color X-Rays," 13 July 2018 Democracy provides less traumatic political means of excising a cancer, including elections. The Economist, "The case against impeachment," 12 July 2018 McCain, who is battling a deadly form of brain cancer from his home in northern Arizona, held the distinction with high respect. Yvonne Wingett Sanchez, azcentral, "U.S. Navy names destroyer after Sen. John McCain," 11 July 2018 Kavanaugh needs only a simple majority of 50 votes for confirmation; there are 51 Republicans in the upper chamber, but Sen. John McCain of Arizona, who is being treated for brain cancer, is unlikely to vote. Nash Jenkins, Time, "Here's What the Key Senators Think About Brett Kavanaugh Right Now," 10 July 2018 Odin was diagnosed with osteosarcoma, a bone cancer, and was given months to live. Danielle Garrand, CBS News, "Woman creates "bucket list" for terminally ill St. Bernard," 5 July 2018 The drug can be used to treat 21 qualifying medical conditions, including cancer, Crohn's disease, epilepsy and other seizure disorders. Randy Tucker,, "First medical marijuana grower gets green light to start planting in Ohio," 29 June 2018 Also included in the cargo are experiments that could eventually help cure cancer, simplify crop science and enhance performance for high-tech medical devices like laser scalpels. Marco Santana,, "SpaceX set to launch 6,000 pounds of science, cargo to International Space Station," 29 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cancer.' 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 cancer

14th century, in the meaning defined at sense 1a

History and Etymology for cancer

Middle English, from Latin (genitive Cancri), literally, crab; akin to Greek karkinos crab, cancer

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Statistics for cancer

Last Updated

6 Nov 2018

Look-up Popularity

Time Traveler for cancer

The first known use of cancer was in the 14th century

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More Definitions for cancer



English Language Learners Definition of cancer

: a serious disease caused by cells that are not normal and that can spread to one or many parts of the body

: something bad or dangerous that causes other bad things to happen

Cancer : the fourth sign of the zodiac that comes between Gemini and Leo and has a crab as its symbol


can·​cer | \ˈkan-sər \

Kids Definition of cancer

: a serious sometimes deadly disease characterized by the growth of abnormal cells that form tumors which may damage or destroy normal body tissue


can·​cer | \ˈkan(t)-sər \

Medical Definition of cancer 

1 : a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis

2 : an abnormal state marked by a cancer

Other Words from cancer

cancerous \ ˈkan(t)s-​(ə-​)rəs \ adjective

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Comments on cancer

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