Plain English Meaning
Watching for other aircraft and changing your flight path when necessary so you don't get too close to them.
Full Definition
The pilot's responsibility and ongoing actions to detect other aircraft and maneuver as needed to prevent a collision, accomplished through visual scanning outside the cockpit, monitoring onboard traffic displays when available, and responding to traffic information or instructions from air traffic control.
Context Anchor
Seen in instrument flying when a pilot is managing other aircraft nearby, especially during approaches, departures, and busy airspace operations.