This is the 14773rd most frequent Russian word.
пласт
"Plast" is a layer, stratum, or sheet, often referring to geological formations or figuratively to layers of something.
The word 'пласт' here is used to denote a layer or a stratum, showing its geological context.
Этот пласт земли содержит полезные ископаемые.
This layer of soil contains minerals.
In this sentence, 'пласт' symbolizes a segment or level within an abstract concept like culture or history.
Пласт культуры, относящийся к XIX веку, богат произведениями искусства.
The stratum of culture related to the 19th century is rich in works of art.
Here, 'пласт' again signifies a layer, this time referring to atmospheric science.