ALL meanings of subgrade
sub·grade
S s - noun subgrade the prepared earth surface on which a pavement or the ballast of a railroad track is placed or upon which the foundation of a structure is built. 1
- adjective subgrade beneath the finished ground level of a project. 1
- noun subgrade the ground beneath a roadway or pavement 0
- noun subgrade a layer of rock or earth leveled and graded for a foundation, as of a road 0