coma

¹ American  

[koh-muh] / ˈkoʊ mə /

noun

plural

comas

1. a state of prolonged unconsciousness, including a lack of response to stimuli, from which it is impossible to rouse a person.

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coma ² American  

[koh-muh] / ˈkoʊ mə /

noun

plural

comae

1. Astronomy. the nebulous envelope around the nucleus of a comet.

2. Optics. a monochromatic aberration of a lens or other optical system in which the image from a point source cannot be brought into focus, the image of a point having the shape of a comet.

3. Botany.

   1. a tuft of silky hairs at the end of a seed.

   2. the leafy crown of a tree; cluster of leaves at the end of a stem.

   3. a terminal cluster of bracts, as in the pineapple.

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coma ¹ British  

/ ˈkəʊmə /

noun

1. astronomy the luminous cloud surrounding the frozen solid nucleus in the head of a comet, formed by vaporization of part of the nucleus when the comet is close to the sun

2. botany

   1. a tuft of hairs attached to the seed coat of some seeds

   2. the terminal crown of leaves of palms and moss stems

3. optics a type of lens defect characterized by the formation of a diffuse pear-shaped image from a point object

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coma ² British  

/ ˈkəʊmə /

noun

1. a state of unconsciousness from which a person cannot be aroused, caused by injury to the head, rupture of cerebral blood vessels, narcotics, poisons, etc

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coma ¹ Scientific  

/ kō′mə /

plural

comae

1. Astronomy The brightly shining cloud of gas that encircles the nucleus and makes up the major portion of the head of a comet near the Sun. As a comet moves along its orbit away from the Sun, the gas and dust of the coma dissipate, leaving only the nucleus. A coma can have a diameter of up to 100,000 km (62,000 mi.).

2. Astronomy See more at comet

3. Physics A diffuse, comet-shaped image of a point source of light or radiation caused by aberration in a lens or mirror. The image appears progressively elongated with distance from the center of the field of view.

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coma ² Scientific  

/ kō′mə /

plural

comas

1. A state of deep unconsciousness, usually resulting from brain trauma or metabolic disease, in which an individual is incapable of sensing or responding to external stimuli.

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coma Cultural  

1. An abnormal state of deep unconsciousness. A coma may occur as the result of trauma to the head, disease (such as meningitis, stroke, or diabetes mellitus), or poisoning.

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Other Word Forms

• comal
  adjective

Etymology

Origin of coma¹

First recorded in 1640–50, coma is from the Greek word kôma deep sleep

Origin of coma²

1660–70; < Latin: hair < Greek kómē

Explanation

Medically speaking, a coma is the state of protective deep sleep your body goes into when severely injured, as in a car crash. Daytime soap operas would be lost without a good coma every few weeks. Coma comes from the Greek koma meaning "deep sleep." As with so many words with medical or scientific origins, coma has been appropriated for a far wider range of uses. The zombie-like trance you fall into at family get-togethers like Thanksgiving? That too is a coma, though your chances of recovery are far better than from a real coma. Unless you happen to sit next to Aunt Sadie.

Example Sentences

Younger age and a higher initial Glasgow Coma Scale score were strong predictors of unexpected survival.

From Science Daily • Feb. 5, 2026

"A Definition of Irreversible Coma" brought the concept of brain death into the vernacular and put the emerging field of organ transplantation front and center within it.

From Salon • Jul. 14, 2023

The term “locked in” was coined in 1966 by neurologists Fred Plum and Jerome Posner in their monograph The Diagnosis of Stupor and Coma.

From Scientific American • Oct. 21, 2022

At the same time, Dr. Laureys of the Coma Science Group said there would be no value in fostering a sense of “false despair” when viable innovations were appearing on the horizon.

From New York Times • Mar. 22, 2022

“Her Glasgow Coma is an eight. Let’s bag her now!” she screams.

From "If I Stay" by Gayle Forman

Related Words

• oblivion
• slumber
• stupor
• trance