stratification

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Formation or deposition of layers, as of rock or sediments.
2. n. The condition of being stratified.
3. n. A layered configuration.

Century Dictionary and Cyclopedia

1. n. The act of stratifying, or the state of being stratified; formation or arrangement in layers.
2. n. Specifically, in geology, deposition in beds or strata: the mode of occurrence of those rocks which have been laid down or spread over the surface by water. The most important indication and result of stratification is that the rock separates more or less easily along the planes separating the beds or strata. Each stratification-plane marks a change in the character of the deposit, or a shorter or longer period during which deposition was suspended. Often one stratum is succeeded by another of quite different character, showing a change in the existing conditions. Sometimes, however, a rock is distinctly stratified, but each stratum separates easily into much thinner layers, closely resembling one another in petrographic character: this is generally called lamination. In some cases the apparent stratification seems to be of the nature of an imperfect cleavage, there having been a certain amount of rearrangement of the particles of the rock parallel to the planes of deposition. See cuts under Artesian and erosion.
3. n. In physiology, the thickening of a cell-wall by the deposition of successive thin layers of formed material; also, the arrangement of the layers so deposited.
4. n. In electricity, the appearance presented by an electric discharge, or a series of rapid discharges, in a rarefied gas, light and dark bands or striæ being produced.

Wiktionary

1. n. the process leading to the formation or deposition of layers, especially of sedimentary rocks
2. n. music a layering of musical texture
3. n. ecology the vertical layering of vegetation in a forest

GNU Webster's 1913

1. n. The act or process of laying in strata, or the state of being laid in the form of strata, or layers.
2. n. (Physiol.) The deposition of material in successive layers in the growth of a cell wall, thus giving rise to a stratified appearance.

WordNet 3.0

1. n. a layered configuration
2. n. the placing of seeds in damp sand or sawdust or peat moss in order to preserve them or promote germination
3. n. forming or depositing in layers
4. n. the act or process or arranging persons into classes or social strata
5. n. the condition of being arranged in social strata or classes within a group