[ kan-ser ]
See synonyms for: cancercancerous on

  1. Pathology.

    • a malignant and invasive growth or tumor, especially one originating in epithelium, tending to recur after excision and to metastasize to other sites.

    • any disease characterized by such growths.

  2. any evil condition or thing that spreads destructively; blight.

  1. genitive Can·cri [kang-kree]. /ˈkæŋ kri/. (initial capital letter)Astronomy. the Crab, a zodiacal constellation between Gemini and Leo.

  2. Cancer, Astrology.

    • the fourth sign of the zodiac: the cardinal water sign.

    • a person born under this sign, usually between June 21 and July 22.

  3. tropic of Cancer. See under tropic (def. 1a).

Origin of cancer

First recorded in 1350–1400; Middle English, from Latin: literally, “crab”; Latin stem cancr-, dissimilated from unattested carcr-, akin to Greek karkínos, Sanskrit karkata “crab”; see canker

Other words for cancer

Other words from cancer

  • can·cer·ous, adjective
  • cancered, adjective
  • can·cer·ous·ly, adverb
  • can·cer·ous·ness, noun
  • non·can·cer·ous, adjective
  • un·can·cer·ous, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use cancer in a sentence

British Dictionary definitions for cancer (1 of 2)


/ (ˈkænsə) /

  1. any type of malignant growth or tumour, caused by abnormal and uncontrolled cell division: it may spread through the lymphatic system or blood stream to other parts of the body

  2. the condition resulting from this

  1. an evil influence that spreads dangerously

Origin of cancer

C14: from Latin: crab, a creeping tumour; related to Greek karkinos crab, Sanskrit karkata

Other words from cancer

  • Related prefix: carcino-

Derived forms of cancer

  • cancerous, adjective
  • cancerously, adverb

British Dictionary definitions for Cancer (2 of 2)


/ (ˈkænsə) /

nounLatin genitive Cancri (ˈkæŋkriː)
  1. astronomy a small faint zodiacal constellation in the N hemisphere, lying between Gemini and Leo on the ecliptic and containing the star cluster Praesepe

  2. astrology

    • Also called: the Crab the fourth sign of the zodiac, symbol ♋, having a cardinal water classification and ruled by the moon. The sun is in this sign between about June 21 and July 22

    • Also called: Moonchild a person born during a period when the sun is in this sign

  1. tropic of Cancer See tropic (def. 1)

  1. astrology born under or characteristic of Cancer

  • Also (for senses 2b, 4): Cancerian (kænˈsɪərɪən)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for cancer (1 of 2)


[ kănsər ]

  1. A disease characterized by any of various malignant neoplasms composed of abnormal cells that tend to proliferate rapidly and invade surrounding tissue. Without treatment such as chemotherapy or radiation, cancer cells can metastasize to other body sites and cause organ failure and death.

  2. A malignant tumor.

a closer look

The human immune system often fights off stray cancer cells just as it does bacteria and viruses. However, when cancer cells establish themselves in the body with their own blood supply and begin replicating out of control, cancer becomes a threatening neoplasm, or tumor. It takes a minimum of one billion cancer cells for a neoplasm to be detectable by conventional radiology and physical examinations. Cancer, which represents more than 100 separate diseases, destroys tissues and organs through invasive growth in a particular part of the body and by metastasizing to distant tissues and organs through the bloodstream or lymph system. Heredity, lifestyle habits (such as smoking), and a person's exposure to certain viruses, toxic chemicals, and excessive radiation can trigger genetic changes that affect cell growth. The altered genes, or oncogenes, direct cells to multiply abnormally, thereby taking on the aggressive and destructive characteristics of cancer. Treatments such as surgery, chemotherapy, and radiation are effective with many cancers, but they also end up killing healthy cells. Gene therapy attempts to correct the faulty DNA that causes the uncontrolled growth of cancer cells. Researchers are investigating other treatments, such as immunotherapy (the stimulation of the body's natural defenses), vectorization (aiming chemicals specifically at cancer cells), and nanotechnology (targeting cancer cells with minute objects the size of atoms).

Scientific definitions for Cancer (2 of 2)


  1. A faint constellation in the Northern Hemisphere near Leo and Gemini. Cancer (the Crab) is the fourth sign of the zodiac.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for cancer


A disease characterized by rapid growth of cells in the body, often in the form of a tumor. Cancer is invasive — that is, it can spread to surrounding tissues. Although this disease is a leading cause of death in the United States, research has provided considerable insight into its many causes (which may include diet, viruses, or environmental factors) and options for treatment (which include radiation, chemotherapy, surgery, and possibly gene therapy).

Notes for cancer

The term cancer is often used to describe a nonmedical condition that is undesirable, destructive, and invasive: “Watergate was a cancer on the presidency.”

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.