stra·tum  (strā'təm, strāt'əm) 
n.
pl. stra·ta (-tə) or stra·tums
A horizontal layer of material, especially one of several parallel layers arranged one on top of another. Geology A bed or layer of sedimentary rock having approximately the same composition throughout. Any of the regions of the atmosphere, such as the troposphere, that occur as layers. Biology A layer of tissue: the epithelial stratum. A level of society composed of people with similar social, cultural, or economic status. One of a number of layers, levels, or divisions in an organized system: a complex poem with many strata of meaning.
[Latin strātum, a covering, from neuter past participle of sternere, to spread; see stratus.]
stra'tal (strāt'l) adj.
Usage Note: The standard singular form is stratum; the standard plural is strata (or sometimes stratums), not stratas. |
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