Definitions

1. noun

A raised road or railway structure carrying a road or railway over a valley or depression, typically supported by piers or viaduct pillars.

“The new viaduct has greatly improved traffic flow through the area.”

2. noun

A long bridge or aqueduct, especially one for carrying a canal or watercourse over a valley or depression.

“The ancient Romans built a viaduct to supply fresh water to the city.”