cancer

noun

can·​cer ˈkan(t)-sər 

1

Cancer

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

4

a

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

b

: a plant disease marked by such growths

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.

Recent Examples on the Web

In the 43-minute sit-down, Kasher detailed discovering the abnormality in his tonsil and how that led to a biopsy that confirmed his cancer diagnosis. —Kimi Robinson, USA Today, 23 June 2026

Rainey died of mesothelioma, a rare type of cancer, surrounded by family in her Walnut Creek home. —Sierra Lopez, Mercury News, 23 June 2026

The measure received broad support in the North Carolina House and has been backed by several lawmakers, including Representative Laura Budd of Mecklenburg County, who has spoken publicly about her breast cancer diagnosis while advocating for the proposal. —Charlotte Observer, 23 June 2026

When cancer death rates peaked in 1991, there was initially little difference between counties with the highest and lowest income levels. —Arthur Cosby, Fortune, 23 June 2026

Word History

Etymology

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

First Known Use

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

Phrases Containing cancer

• cancer stick
• small-cell lung cancer

Rhymes for cancer

• ansar
• anser
• answer
• dancer
• lancer
• anticancer
• necromancer
• enhancer
• merganser
• romancer

Kids Definition

cancer

noun

can·​cer ˈkan(t)-sər 

1

capitalized : a group of stars between Gemini and Leo usually pictured as a crab

2

capitalized

a

: the fourth sign of the zodiac see zodiac

b

: a person whose sign of the zodiac is Cancer

3

: a tumor that tends to spread locally and to other parts of the body and often causes death if not treated

also : an abnormal state marked by such tumors

4

: a dangerous evil that destroys slowly

cancerous

ˈkan(t)s-(ə-)rəs 

adjective

Etymology

Middle English Cancer "'Crab' star group," from Latin cancer "crab, cancer (disease)"; sense 3 directly from Latin cancer "crab, cancer" — related to canker, chancre

Word Origin

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.

Medical Definition

cancer

noun

can·​cer ˈkan(t)-sər 

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

cancerous

ˈkan(t)s-(ə-)rəs 

adjective