Yes, coma is a Scrabble word!

Noun

1. A state of deep and often prolonged unconsciousness; usually the result of disease or injury

2. (botany) a usually terminal tuft of bracts (as in the pineapple) or tuft of hairs (especially on certain seeds)

3. (astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed