thalweg vs contour

thalweg and contour both are nouns.

Word	Noun	Adjective	Verb	Adverb
thalweg	Yes	No	No	No
contour	Yes	No	Yes	No

As nouns, contour is a hypernym of thalweg; that is, contour is a word with a broader meaning than thalweg:

Other hypernyms of thalweg include contour line.

thalweg (noun)	contour (noun)
a line following the lowest points of a valley	any spatial attributes (especially as defined by outline)
the middle of the chief navigable channel of a waterway that forms the boundary line between states	a feature (or the order or arrangement of features) of anything having a complex structure
	a line drawn on a map connecting points of equal height

thalweg (verb)	contour (verb)
	form the contours of