keyline

About 0.01 uses per million words.

Meaning

1. noun A contour line connecting all points in valley at the same elevation as the keypoint, used in planning efficient water usage.
2. noun A boundary line that separates color and monochromatic areas or differently colored areas of print.

Similar words

keypoint contour line thalweg equipluve waterline isoline groundline contour centrolinead cloudline

Often followed by

to and plan is around