Foothill and Gradient

Foothill noun - A relatively low hill on the lower slope of a mountain.

Gradient and foothill are semantically related. In some cases you can use "Gradient" instead a noun "Foothill".

Gradient noun - The degree to which something rises up from a position level with the horizon.

Foothill and gradient are semantically related. Sometimes you can use "Foothill" instead a noun "Gradient".