//www.medicinenet.com/sleep/article.htm">sleep: NREM (non-rapid eye movement) sleep is dreamless sleep. During NREM, the brain waves on the electroencephalographic (EEG) recording are typically slow and of high voltage, the breathing and heart rate are slow and regular, the blood pressure is low, and the sleeper is relatively still. NREM sl [..]

(n) a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur; accounts for about 75% of normal sleep time

is usually used attributively beforeto refer to sleep stages 1–3 (previously 1–4), but can be used alone for the same en|denotation.