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 resentment — Irish 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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Merriam-Webster unabridged
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The first known use of cancer was in the 14th century
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