/tahl"veg, -vayk/ , n.
1. a line, as drawn on a map, connecting the lowest points of a valley.
2. Chiefly Internat. Law. the middle of the main navigable channel of a waterway that serves as a boundary line between states.
[ 1860-65; Thal, now obs. sp. of Tal valley (c. DALE) + Weg WAY 1 ]