In the R&K standard, NREM sleep was divided into four stages, with slow-wave sleep comprising stages 3 and 4. In stage 3, delta waves made up less than 50% of the total wave patterns, while they made up more than 50% in stage 4. Furthermore, REM sleep was sometimes referred to as stage 5.
Freebase(0.00 / 0 votes)Rate this definition: Turret. In architecture, a turret is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification.
1 (military) A gentle incline in front of a fortification. ( 2 military) The angled armour plate on the front of a tank; glacis plate. ( 3 postal service) A device for sorting mail which slides parcels across a sloped surface.