Definitions

1. noun

A layer or stratum of rock or soil; a substratum.

“The geologist studied the different substrata found in the sedimentary rock.”

2. noun

A stratum or layer of something, especially in a social or cultural sense.

“The substrata of class divisions within the community were evident at the protest.”

3. plural noun

Substances or materials that form a basis or foundation for something.

“The substrata of the new paint job included a layer of primer and a coat of varnish.”