n. a state of deep and often prolonged unconsciousness; usually the result of disease or injury
n. (botany) a usually terminal tuft of bracts (as in the pineapple) or tuft of hairs (especially on certain seeds)
n. (astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed
n. <医>昏迷( coma的复数形式 )