stra·tum 
/ˈstreɪtəm, Brit ˈstrɑ:təm/ noun
plural stra·ta /ˈstreɪtəm, Brit ˈstrɑ:təm/ noun /ˈstreɪtə, Brit ˈstrɑ:tə/ [count] 1 : one of usually many layers of a substance (such as rock)
▪ a rock stratum ▪ a stratum of earth 2 : a level of society made up of people of the same rank or position
▪ Drug abuse is a problem in every stratum of society. = Drug abuse is a problem in all social strata.
▪ a rock stratum ▪ a stratum of earth
▪ Drug abuse is a problem in every stratum of society. = Drug abuse is a problem in all social strata.
