noun
- a bridge for carrying a road, railroad, etc., over a valley or the like, consisting of a number of short spans.
noun
- a bridge, esp for carrying a road or railway across a valley, etc, consisting of a set of arches supported by a row of piers or towers
1816, from Latin via “road” (see via) + -duct as in aqueduct. French viaduc is an English loan-word.