Westbound means traveling or heading toward the west. When a train is westbound, it's moving in the direction where the sun sets. If you're on a westbound flight from New York to California, you're flying across the country toward the Pacific Ocean.

The word works like a compass direction combined with movement. A westbound highway lane carries traffic toward the west, while the eastbound lanes on the other side carry traffic the opposite way. Ships can be westbound across the Atlantic, buses can be westbound on Main Street, and hikers can be westbound on a trail.

You'll often see this word on road signs, in train stations, and in traffic reports: “Take the westbound exit” or “Westbound traffic is delayed.” The word tells you both a direction and that something is actively moving or meant to move that way. A westbound journey is one where west is your destination or the direction you're traveling, whether you're going two blocks or two thousand miles.