coma

¹ American  

[koh-muh] / ˈkoʊ mə /

noun

• comas
  plural

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

• comae
  plural

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 /

• comae
  plural

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 /

• comas
  plural

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

Derived Forms

• comal
  adjective

Inflected Forms

Nouns

• comae
  plural
• comas
  plural

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

See Examples For:

coma comae comas

In 2025, a jury awarded nearly $49 million to a man in a coma after he was hit by a city garbage truck driver, who was accused of making an “unsafe right turn.”

From Los Angeles Times ● Aug. 22, 2026

It came just months after she was treated in intensive care after being placed in an induced coma following an emergency intestinal surgery.

From Barron's ● Aug. 15, 2026

When people eat these contaminated shellfish or fish, they can get Amnesic Shellfish Poisoning, which can lead to vomiting, diarrhea, permanent short-term memory loss, coma or death.

From Los Angeles Times ● Jul. 29, 2026

He is now in an induced coma with a machine performing the usual function of the heart.

From BBC ● Jul. 21, 2026

“Do not leap. Do not move abruptly. If you don’t promise to take it easy, I’ll slow your heart and keep you in a coma until I can be sure you’ve recovered fully.”

From "Six of Crows" by Leigh Bardugo

If it is dry the accused is held to be guilty—fear has stopped the secretion of saliva—obstupui, stetetuntque comae, et vox faucibus haesit.

From Criminal Psychology; a manual for judges, practitioners, and students by Hans Gustav Adolf Gross

The nuclei and comae of different comets exhibit few peculiarities to the unaided vision except in respect to brightness; but the tails of comets differ widely, both in brightness and in extent.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7 "Columbus" to "Condottiere" by Various

As often as the thought had comae to me I had thrust it away.

From The Betrayal by E. Phillips (Edward Phillips) Oppenheim

In December, 15-month-old Louie and Vinnie Hughes were placed in induced comas as they fought to survive the disease.

From BBC ● Jan. 3, 2025

Centers for Disease Control and Prevention, methyl bromide can cause lung disease, convulsions, comas and ultimately death.

From Seattle Times ● Feb. 13, 2024

For the current study, she and her team looked at the medical records of four people who were in comas and on life support on whom physicians had placed electroencephalography caps.

From Science Magazine ● May 1, 2023

The lawsuit names four people — Medina Leon and three men who were released while they were hospitalized and had fallen into comas.

From Los Angeles Times ● May 13, 2022

All this business about medically induced comas is just doctor talk.

From "If I Stay" by Gayle Forman

Related Words

• oblivion
• slumber
• stupor
• trance