Plain English Meaning
Using a GPS unit to help find your way when flying by visual rules. The GPS shows where you are and where you're going, but you still have to look outside, use your charts, and not rely on the GPS alone.
Full Definition
The use of a Global Positioning System receiver as a navigation aid during flight conducted under Visual Flight Rules. When used for VFR navigation, GPS supplements pilotage and dead reckoning but does not replace the requirement to see and avoid other aircraft, maintain visual reference to the ground or landmarks where required, and carry and use appropriate . The receiver may be panel-mounted certified equipment or a portable unit, and remains responsible for verifying , signal , and .