Plain English Meaning
Drawing the planned route on a chart and working out the details of how to get from where you're starting to where you're going.
Full Definition
The pilot's process of selecting and drawing the intended route of flight on an aeronautical chart, including marking the course line between departure and destination, identifying checkpoints along the route, measuring distances and true courses, and noting terrain, airspace, and obstacles that affect the flight.
Context Anchor
Seen during cross-country flight planning, before the pilot calculates headings, needs, time, and other flight details.