coma -
A tuft or bunch, such as the assemblage of branches forming the head of a tree, a cluster of bracts when empty and terminating the inflorescence of a plant, or a tuft of long hairs on certain seeds.
Wikipedia
A coma (from the Greek κῶμα koma, meaning deep sleep) is a profound state of unconsciousness. A person in a coma cannot be awakened, fails to respond normally to pain, light or sound, does not have sleep-wake cycles, and does not take voluntary actions. A person in a state of coma can be described as comatose.
OmegaWiki Dictionary
Ω
coma A state of unconsciousness from which one may not wake up, usually induced by some form of trauma.
coma A cloud of dust surrounding the nucleus of a comet.
coma An optical aberration in an astronomical telescope which causes a V-shaped flare to the image of a star.