Plain English Meaning
The short period just before takeoff when the pilot does the last set of checks and confirms everything is ready to go.
Full Definition
The phase of flight operations occurring after engine start and taxi but before the aircraft begins its takeoff roll, during which the pilot completes final checks, runs the pretakeoff checklist, briefs the departure, and confirms the aircraft and crew are ready for flight.
Context Anchor
Used in instructor guidance, checklists, briefings, and risk-management discussions for the period before departure.