coma (n.1)

state of prolonged unconsciousness, 1640s, from Latinized form of Greek koma (genitive komatos) "deep sleep," which is of uncertain origin. A term for "coma" in Middle English was false sleep (late 14c.).

coma (n.2)

"head of a comet," 1765, from Latin coma, from Greek kome "hair of the head," which is of unknown origin. Earlier in English as a botanical term for a tuft of hairs (1660s).