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.
Definition of CASTLE for Kids. 1. : a large building or group of buildings usually having high walls with towers that was built in the past to protect against attack. 2. : a large or impressive house.ull Definition of CASTLE. 1. a: a large fortified building or set of buildings b: a massive or imposing house. 2. : a retreat safe against intrusion or invasion. 3. : 3rook. See castle defined for English-language learners. See castle defined for kids.