1. a state of deep and often prolonged unconsciousness; usually the result of disease or injury (Freq. 1) • Syn: comatoseness • Derivationally related forms: comatose (for: comatoseness) • Hypernyms: unconsciousness • Hyponyms: diabetic coma, Kussmaul's coma, hepatic coma 2.(botany) a usually terminal tuft of bracts (as in the pineapple) or tuft of hairs (especially on certain seeds) • Derivationally related forms: comal • Topics: botany, phytology • Hypernyms: tuft, tussock 3.(astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed • Topics: astronomy, uranology • Hypernyms: cloud • Part Holonyms: comet