thalweg

[tahl-veg, -veyk]

noun

a line, as drawn on a map, connecting the lowest points of a valley.
Chiefly International Law. the middle of the main navigable channel of a waterway that serves as a boundary line between states.

Origin of thalweg

1860–65; < German, equivalent to Thal, now obsolete spelling of Tal valley (cognate with dale) + Weg way¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for thalweg

Historical Examples of thalweg

The thalweg has been frequently confirmed as the accepted boundary where no conventions to the contrary existed.
International Law
George Grafton Wilson and George Fox Tucker

British Dictionary definitions for thalweg

thalweg

talweg

noun geography rare

the longitudinal outline of a riverbed from source to mouth
the line of steepest descent from any point on the land surface

Word Origin for thalweg

C19: from German, from Thal valley + Weg way, path

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for thalweg

1831, from German Thalweg "path along the bottom of a valley," from thal (see dale) + weg (see way).

thalweg in Science

thalweg

[täl′vĕg′]

The line defining the lowest points along the length of a river bed or valley, whether underwater or not.
A subterranean stream following a course similar to that of an overlying surficial stream.