subsurface
adjEtymology From sub- + surface.
1
Below the surface.
- variations in subsurface conditions
subsurface
nounEtymology From sub- + surface.
1
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
Mathematics, Sciences A surface which is a submanifold of another surface.