subsurface

About 1.55 uses per million words.

Meaning

1. noun Something that is below the layer that is on the surface.

   Before we could lay the flooring we had to lay a subsurface under it to keep it flat and support it.

2. noun A surface which is a submanifold of another surface.
3. adjective Below the surface.

   variations in subsurface conditions

Similar words

underground belowground subterranean underwater undersea submerged submarine submersed subsea groundwater

Often followed by

water flow drainage conditions waters of and geology layer

Word family

subsurfaces