coma Meaning, Definition & Usage

  1. noun a state of deep and often prolonged unconsciousness; usually the result of disease or injury
    comatoseness.
  2. noun (botany) a usually terminal tuft of bracts (as in the pineapple) or tuft of hairs (especially on certain seeds)
  3. noun (astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed

WordNet

Co"ma noun
Etymology
NL., fr. Gr. lethargy, fr. to put to sleep. See Cemetery.
Definitions
  1. A state of profound insensibility from which it is difficult or impossible to rouse a person. See Carus.
Co"ma noun
Etymology
L., hair, fr. Gr. .
Definitions
  1. (Astron.) The envelope of a comet; a nebulous covering, which surrounds the nucleus or body of a comet.
  2. (Bot.) A tuft or bunch, -- as the assemblage of branches forming the head of a tree; or a cluster of brachts when empty and terminating the inflorescence of a plant; or a tuft of long hairs on certain seeds.

Webster 1913