Plain English Meaning
Everything you think through and check before you take off, so you arrive at the airplane already knowing what you're going to do, where you're going to do it, and what conditions you'll be flying in.
Full Definition
The work a pilot does before a flight to prepare for it safely and legally. For ground reference maneuvers, this includes selecting a suitable practice area, checking weather and winds, identifying landmarks and emergency landing options, noting obstructions and populated areas to avoid, and confirming the airplane is airworthy and within weight and balance limits.
Context Anchor
In this , preflight planning shows up before , where must a safe practice area and account for , , , and possible areas.