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.
A modern gun turret (A French 100 mm naval gun on the MaillÃ©-BrÃ©zÃ© pictured) allows firing of the cannons via remote control. Loading of ammunition is also often done by automatic mechanisms. A gun turret is a location from which weapons can be fired that affords protection, visibility, and some cone of fire. A modern gun turret is generally a weapon mount that houses the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in some degree of azimuth and elevation (cone of fire).