stratum
/ˈstreɪtəm/
noun
- A layer of rock, soil, or other material in the ground, especially one of several parallel layers.
- The geologist studied each stratum of rock to learn about the area's history.
- Fossils found in the upper stratum were younger than those in the lower one.
- A thin stratum of clay separated the two layers of sand.
- A level or class in society, an organization, or a system.
- The new policy affected every stratum of society, from the poorest to the richest.
- Education can help people move from one social stratum to another.
- Within the company, each stratum of management has different responsibilities.