2) oil sand. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...A stratum of sand or sandstone containing petroleum....

3) strata. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...A plural of stratum....

4) overclass. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...The upper social stratum of society, composed of wealthy and professional people, especially when viewed as controlling society's economic power....

5) underclass. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...The lowest societal stratum, usually composed of the disadvantaged: Divorced women and their children are becoming a new underclass (Barbara Fisher Williamson)....

6) stratum. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...such as the troposphere, that occur as layers. 4. Biology A layer of tissue: the epithelial stratum. 5. A level of society composed of people with similar social,...

7) stratum corneum. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...horny outer layer of the epidermis, consisting mainly of dead or peeling cells. New Latin : stratum + Latin corneum, neuter of corneus, horny; see cornea....

8) lumpenproletariat. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...1. The lowest, most degraded stratum of the proletariat. Used originally in Marxist theory to describe those members of the proletariat, especially criminals, vagrants,...

9) outcrop. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...A portion of bedrock or other stratum protruding through the soil level. Inflected forms: outˇcropped, outˇcropˇping, outˇcrops(out-krp) To protrude above the soil,...

10) straticulate. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...Geology Having thin layers. From stratum.straˇticuˇlation (-lshn) -NOUN...