Plain English Meaning
If one of the cockpit screens stops working, the other screen automatically rearranges itself to show all the most important flight information on that one screen so the pilot can keep flying safely.
Full Definition
A backup display mode in a glass cockpit (electronic flight display) system that consolidates the primary flight instruments and engine information onto a single working screen when the other screen fails. The remaining display reverts to showing all critical flight data so the pilot retains the essential information needed to fly the aircraft.
Context Anchor
Seen in glass-cockpit aircraft when discussing what happens after a cockpit display fails, especially during instrument flying or display-failure training.