coma Definition

coma¹
noun

comas
1. A prolonged state of deep unconsciousness from which a person cannot be awakened, caused by head injury, brain damage, stroke, etc.

Thesaurus: unconsciousness, catalepsy, insensibility, stupor, lethargy, oblivion, somnolence, torpor.

Etymology: 17c: from Greek koma deep sleep.

---

coma²
noun comae

1. bot.
A tuft of hairs attached to the testa of some seeds.
2. bot.
The arrangement of leaves at the top of a tree.
3. astron.
The envelope of gas and dust which forms around the nucleus of a comet.
4. optics.
A defect in an optical system or the manifestation of it in which the image of a point appears as a blurred pear shape.

Etymology: 17c: Latin, from Greek kome hair of the head.