Definition of cancer
1 capitalized a : a northern zodiacal constellation between Gemini and Leob (1) : the fourth sign of the zodiac in astrology — see 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 (see malignant 2) tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis (see metastasis 1b)b : an abnormal bodily state marked by such tumors
3 : something evil or malignant that spreads destructively the cancer of hidden resentment — Irish Digest
4a : an enlarged tumorlike plant growth (as that of crown gall)b : a plant disease marked by such growths
cancerousplay \ˈkan(t)s-rəs, ˈkan(t)-sə-\ adjective
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.
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.
Origin and Etymology of cancer
Middle English, from Latin (genitive Cancri), literally, crab; akin to Greek karkinos crab, cancer
First Known Use: 14th century
CANCER Defined for English Language Learners
Definition of cancer for English Language Learners
: 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
CANCER Defined for Kids
Definition of cancer for Students
: a serious sometimes deadly disease characterized by the growth of abnormal cells that form tumors which may damage or destroy normal body tissue
Seen and Heard
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