Is “Viaduct” a Scrabble word?
Yes
VIADUCT
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Viaduct
/ˈvaɪəˌdʌkt/
noun
1.A bridge with several spans that carries road or rail traffic over a valley or other obstacles.