1.Definition: a subpopulation divided into a stratified sampling

Category: General

2.Definition: an abstract place usually conceived as having depth

Related Noun(s):layer, level

Category: General

3.Definition: one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)

Category: Places

4.Definition: people having the same social, economic, or educational status

Related Noun(s):class

Category: General