Plain English Meaning
A turn made while the airplane is gliding down with the engine pulled back, instead of turning in level flight with normal power.
Full Definition
A turn performed with the engine at idle (or at reduced power) while the airplane descends along a curved path. Bank angle, airspeed, and rate of descent must be coordinated so the airplane maintains a stable glide throughout the turn rather than a level or climbing flight path.
Context Anchor
Used in steep spirals, emergency descent practice, and situations where a pilot needs to turn while descending without relying on engine power.