tropic of Cancer
- trophy room,
- trophy wife,
- tropic bird,
- tropic of cancer,
- tropic of capricorn,
- tropical abscess
Origin of tropic of Cancer
- either of two corresponding parallels of latitude on the terrestrial globe, one (tropic of Cancer) about 23½° N, and the other (tropic of Capricorn) about 23½° S of the equator, being the boundaries of the Torrid Zone.
- the tropics, the regions lying between and near these parallels of latitude; the Torrid Zone and neighboring regions.
Origin of tropic
- 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.
- the fourth sign of the zodiac: the cardinal water sign.
- a person born under this sign, usually between June 21 and July 22.
Origin of cancer
Word Origin for cancer
noun Latin genitive Cancri (ˈkæŋkriː)
- 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
Word Origin for tropic
late 14c., "either of the two circles in the celestial sphere which describe the northernmost and southernmost points of the ecliptic," from Late Latin tropicus "of or pertaining to the solstice" (as a noun, "one of the tropics"), from Latin tropicus "pertaining to a turn," from Greek tropikos "of or pertaining to a turn or change, or to the solstice" (as a noun, "the solstice"), from trope "a turning" (see trope).
The notion is of the point at which the sun "turns back" after reaching its northernmost or southernmost point in the sky. Extended 1520s to the corresponding latitudes on the earth's surface (23 degrees 28 minutes north and south); meaning "region between these parallels" is from 1837. Tropical "hot and lush like the climate of the tropics" is first attested 1834.
Old English cancer "spreading sore, cancer" (also canceradl), from Latin cancer "a crab," later, "malignant tumor," from Greek karkinos, which, like the Modern English word, has three meanings: crab, tumor, and the zodiac constellation (late Old English), from PIE root *qarq- "to be hard" (like the shell of a crab); cf. Sanskrit karkatah "crab," karkarah "hard;" and perhaps cognate with PIE root *qar-tu- "hard, strong," source of English hard.
Greek physicians Hippocrates and Galen, among others, noted similarity of crabs to some tumors with swollen veins. Meaning "person born under the zodiac sign of Cancer" is from 1894. The sun being in Cancer at the summer solstice, the constellation had association in Latin writers with the south and with summer heat. Cancer stick "cigarette" is from 1959.
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).
Tropic of Cancer
Tropic of 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).