subsoil

noun, verb — 2 senses

subsoil

noun

/ˈsʌbsɔɪl/

Etymology From sub- + soil.

1

The layer of earth that is below the topsoil.

In the few areas underlain by horizontally bedded limestone, the surface soil is dark gray to black and peatlike, and the subsoil gray and marllike.1954, Soil survey of Wise County, Virginia, page 28:

subsoil

verb

Etymology From sub- + soil.

1

To turn up the subsoil of.

Derived terms: subsoiler

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.