coma 1
/koh"meuh/ , n. , pl. comas .
a state of prolonged unconsciousness, including a lack of response to stimuli, from which it is impossible to rouse a person.
[ 1640-50; kôma deep sleep ]
coma 2
/koh"meuh/ , n. , pl. comae /-mee/ .
1. Astron. 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. Bot.
a. a tuft of silky hairs at the end of a seed.
b. the leafy crown of a tree; cluster of leaves at the end of a stem.
c. a terminal cluster of bracts, as in the pineapple.
[ 1660-70; kóme ]