Thalweg
Pronunciation : Thal"weg`, n. [G., fr. thal valley + weg way. See Dale; Way.] (Physiography) (a) A line following the lowest part of a valley, whether under water or not. (b) The line of continuous maximum descent from any point on a land surface
Part of Speech : or
Definition :
that cutting all contours and angles.
Source : Webster's Unabridged Dictionary, 1913