Definitions

1. noun

Layers or a layer of rock, soil, or other material beneath the surface of the earth.

“The geologists studied the different substrata of rock formations in the area.”

2. noun

Lower strata or levels of a system, especially a social or cultural system.

“The social substrata of the community were deeply affected by the economic crisis.”

3. noun

A lower layer or stratum.

“The substrata of the forest floor supported a diverse array of plant and animal life.”