Plain English Meaning

The blade position where the propeller blades are turned edge-on to the wind so they slice through the air instead of pushing against it. This stops the propeller from spinning and greatly reduces drag when an engine is shut down in flight.

Full Definition

The propeller blade angle in which the blades are rotated parallel to the oncoming airflow, presenting their thinnest edge forward to minimize aerodynamic drag and stop propeller rotation after engine shutdown in flight.

Context Anchor

Seen in discussions of feathering propellers, especially on airplanes where a failed engine’s propeller can be adjusted to reduce drag.