nightwalking [AS, niht + ME, walken] , a disorder occurring during nonrapid eye movement sleep in which the subject usually sits up in bed briefly, then gets up and walks around, opening doors, eating, and so on, and eventually returns to bed. The person has no memory of the event the next day. Nightwalking is sometimes associated with the use of sleep medication. Also called noctambulation, sleepwalking, somnambulism.
