Plain English Meaning
A digital screen that shows you which way the aircraft is pointed, the course you've selected, and how well you're tracking it — all in one picture.
Full Definition
An electronic cockpit display that shows the aircraft's heading, course, and navigation information on a single screen, replacing the traditional mechanical horizontal situation indicator. It typically presents a compass rose, course deviation indicator, bearing pointers, and selected navigation source, and is integrated into a primary flight display or multifunction display in a glass cockpit.
Context Anchor
Seen in glass-cockpit airplanes during navigation, instrument flying, and , especially when checking what course or navigation source the display is using.