- 1(geology) a layer or set of layers of rock, earth, etc. a thick stratum of flint limestone strata Excavated coins can often be dated from other objects in the same stratum.
- 2(formal) a class in a society people from all social strata
NAmE//ˈstreɪt̮əm//, NAmE//ˈstræt̮əm//(pl. strata