coma
deep prolonged unconsciousness
Not to be confused with:comma – punctuation mark (,) that indicates a pause in a sentence:
A misplaced comma can convey a very different meaning. Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree
co·ma 1
(kō′mə)n. pl. co·mas A state of deep, often prolonged unconsciousness, usually the result of injury, disease, or poison, in which an individual is incapable of sensing or responding to external stimuli and internal needs.
[Greek kōma, deep sleep.]
co·ma 2
(kō′mə)n. pl. co·mae (-mē) 1. Astronomy The nebulous luminescent cloud surrounding the nucleus of a comet and composed of material evaporated from the nucleus when the comet is near the perihelion of its orbit. The nucleus and coma together form the head of a comet.
2. Botany A usually terminal tuft or cluster, especially a tuft of hairs on a seed, as on a willow or milkweed seed.
3. Physics A diffuse, comet-shaped image of a point source of light or radiation caused by aberration in an optical system.
[Latin, hair, from Greek komē.]
co′mal adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
coma
(ˈkəʊmə) n,
pl -mas (Pathology) 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
[C17: from medical Latin, from Greek kōma heavy sleep; related to Greek koitē bed, perhaps to Middle Irish cuma grief]
coma
(ˈkəʊmə) n,
pl -mae (
-miː)
1. (Astronomy) 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)
botany a. a tuft of hairs attached to the seed coat of some seeds
b. the terminal crown of leaves of palms and moss stems
3. (General Physics) optics a type of lens defect characterized by the formation of a diffuse pear-shaped image from a point object
[C17: from Latin: hair of the head, from Greek komē]
ˈcomal adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
co•ma1
(ˈkoʊ mə)
n., pl. -mas. a state of prolonged unconsciousness, including a lack of response to stimuli, from which it is impossible to rouse a person.
[1640–50; < Greek kôma deep sleep]
co•ma2
(ˈkoʊ mə)
n., pl. -mae (-mē). 1. the nebulous envelope around the nucleus of a comet.
2. a monochromatic aberration of a lens or other optical system in which the image from a point source cannot be focused.
3. a tuft of hairs on a seed or a terminal cluster of leaves or bracts, as on a stem.
[1660–70; < Latin: hair < Greek kómē]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
co·ma 1
(kō′mə) A state of deep unconsciousness resulting from disease or injury, from which a person cannot be aroused. A person in a coma usually is unable to respond to events taking place outside the body.
coma 2
The brightly shining cloud of gas that encircles the nucleus and makes up the major portion of the head of a comet that is near the sun.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.