This is the 14776th most frequent Russian word.
пластины
"Plates" or "sheets" (thin, flat pieces of material).
Here, "пластины" refers to physical flat layers or plates that are part of an apparatus.
Я купил резервные пластины для своего термостата.
I bought spare plates for my thermostat.
In this usage, "пластины" refers to tectonic plates, indicating large layers of the Earth's crust.
Геолог изучил структуру земных пластин для своей диссертации.
The geologist studied the structure of the Earth's plates for his dissertation.
In this case, "пластины" could refer to data storage plates or flat components used in scientific experiments.