| coma [`kō·mǝ] ASTRONOMY The gaseous envelope that surrounds the nucleus of a comet. Also known as head. ELECTRONICS A cathode-ray tube image defect that makes the spot on the screen appear comet-shaped when away from the center of the screen. MEDICINE Unconsciousness from which the patient cannot be aroused. OPTICS A manifestation of errors in an optical system, so that a point has an asymmetrical image (that is, appears as a pear-shaped spot). |