underlayer

About 0.04 uses per million words.

Meaning

1. noun A layer that is below another layer.
2. noun A perpendicular shaft sunk to cut the lode at any required depth.
3. noun One who underlays.
4. verb To form a layer beneath another

Similar words

cr sublayer substratum underlay overstratum subsurface underlier understratum submonolayer undercovering

Often followed by

of and is to for in was on thickness