The acronym DEEP SLEEP stands for 'Dissociative Experiences of Everyday Psychosis, ' a term coined by psychiatrist and psychoanalyst Dr. Ernest Hartmann in the 1980s. The crossword solution for this acronym is COMA, which stands for 'Continuous Obstructive Mental Activity.' This term refers to a state of unconsciousness in which a person is unable to respond to external stimuli or be aroused from sleep. It is usually caused by a severe injury or illness, and can last for days or weeks.