Coma

A state of profound insensibility from which it is difficult or impossible to rouse a person. See Carus.

The envelope of a comet; a nebulous covering, which surrounds the nucleus or body of a comet.

A tuft or bunch, -- as the assemblage of branches forming the head of a tree; or a cluster of bracts when empty and terminating the inflorescence of a plant; or a tuft of long hairs on certain seeds.

(astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed

(botany) a usually terminal tuft of bracts (as in the pineapple) or tuft of hairs (especially on certain seeds)

a state of deep and often prolonged unconsciousness; usually the result of disease or injury