1. a state of deep unconsciousness caused by disease, injury, or poison, in which a person cannot be awakened
Usage: medical
2. the bright cloud of gas and dust that surrounds the nucleus of a comet
Usage: astronomy

Examples

• The accident victim remained in a coma for three weeks.
• Doctors are monitoring her brain activity while she’s in the coma.
• He slipped into a diabetic coma due to his blood sugar levels.
• The family kept vigil while their father was in a coma.
• As the comet approached the sun, its coma became more visible.
• The telescope revealed the comet’s bright coma surrounding its nucleus.
• Astronomers studied the composition of gases in the comet’s coma.