SUBSURFACE
subsurface
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 supoort it.
- A surface which is a submanifold of another surface.
Adjective
- below the surface
- variations in subsurface conditions
The above text is a snippet from Wiktionary: subsurface
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