stratum
n pl , -ta , -tums
1 usually pl any of the distinct layers into which sedimentary rocks are divided
2 (Biology) a single layer of tissue or cells
3 a layer of any material, esp. one of several parallel layers
4 a layer of ocean or atmosphere either naturally or arbitrarily demarcated
5 a level of a social hierarchy that is distinguished according to such criteria as educational achievement or caste status (C16: via New Latin from Latin: something strewn, from sternere to scatter) ♦
stratal adj
stratum title
n the N.Z. name for →
strata title