coma (n.1) Look up coma at Dictionary.com
state of prolonged unconsciousness, 1640s, from Latinized form of Greek koma (genitive komatos) "deep sleep," of uncertain origin.
coma (n.2) Look up coma at Dictionary.com
"head of a comet," 1765, from Latin coma, from Greek kome "hair of the head," of unknown origin. Earlier in English as a botanical term for a tuft of hairs (1660s).