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.
The right or left side of a military formation: an attack on both flanks. b. The right or left side of a bastion. tr.v. flanked, flankÂ·ing, flanks. 1. To protect or guard the flank of. 2. To menace or attack the flank of. 3. To be placed or situated at the flank or side of: Two stone lions flanked the entrance. 4. To put (something) on each side of: flanked the driveway with tall shrubs.