viaduct Meaning, Definition & Usage

  1. noun bridge consisting of a series of arches supported by piers used to carry a road (or railroad) over a valley

WordNet

Vi`a*duct noun
Etymology
L. via a way + -duct, as in aqueduct: cf. F. viaduc. See Via, and Aqueduct.
Definitions
  1. A structure of considerable magnitude, usually with arches or supported on trestles, for carrying a road, as a railroad, high above the ground or water; a bridge; especially, one for crossing a valley or a gorge. Cf. Trestlework.

Webster 1913