stratification

noun

1. (countable, uncountable)The process leading to the formation or deposition of layers, especially of sedimentary rocks.

   “He has misunderstood the English excavators in regard to the stratification of Knossos. He has wrongly imagined that the West Court of Knossos and a great part of the whole west wing belonged to an earlier building, contemporary with the West Court of Phæstos, and that they were later superseded and partly covered over by a later structure, contemporary with the supposed mainland Achæan type of Megaron at Phæstos that is now proved to be no Megaron at all.”

2. (countable, uncountable)A layering of musical texture.
3. (countable, uncountable)The vertical layering of vegetation in a forest.
4. (countable, uncountable)Society's categorization of people into socioeconomic strata.
5. (countable, uncountable)The process of treating seeds to simulate natural conditions that the seeds must experience before germination can occur, often involving exposure to cold.
6. (countable, uncountable)A classification or arrangement of things into different categories or groups.