Stratum

GRE Barron TOEFL

[编辑] 解释

noun (plural strata)

Etymology: New Latin, from Latin, spread, bed, from neuter of stratus, past participle of sternere to spread out — more at strew
Date: 1599
1. a bed or layer artificially made
2.
- a. a sheetlike mass of sedimentary rock or earth of one kind lying between beds of other kinds
- b. a region of the sea or atmosphere that is analogous to a stratum of the earth
- c. a layer of tissue <deep stratum of the skin>
- d. a layer in which archaeological material (as artifacts, skeletons, and dwelling remains) is found on excavation
3.
- a. a part of a historical or sociological series representing a period or a stage of development
- b. a socioeconomic level of society comprising persons of the same or similar status especially with regard to education or culture
4. one of a series of layers, levels, or gradations in an ordered system <strata of thought>
5. a statistical subpopulation
Usage:
- The plural strata has occasionally been used as a singular since the 18th century and is sometimes given the plural stratas <there was a strata of Paris which mere criticism of books fails to get hold of — Ezra Pound><a Roman burial ground suggests stratas of corruption and decay — Connie Fletcher, Booklist>. Current evidence shows senses 2, 3b, and 4 so used, with 3b the most common. Singular strata is persistent but not frequent. Strata may someday establish itself as a singular like agenda, but that use is still not established.