Descending far below the surface; opening or reaching to great depth; deep.
Intellectually deep; entering far into subjects; reaching to the bottom of a matter, or of a branch of learning; thorough
Very deep; very serious
Characterized by intensity; deeply felt; pervading
Bending low, exhibiting or expressing deep humility; lowly; submissive
below the surface
A surface which is a submanifold of another surface.
Something that is below the layer that is on the surface.