1Geology and Archaeology. Designating rock, sediment, remains, etc., that show stratification or are deposited in strata. Also, of a fossil or artefact: used to date a stratum, or identified as belonging to a particular stratum.

2Chiefly Biology and Medicine. Designating a tissue or substance that has a layered structure, or is composed of layers with differing properties.

3Botany. Of seeds: subjected to treatment by stratification for the purpose of preserving them, or (typically) to promote germination.

4Of a volume of gas (especially the atmosphere) or of liquid (especially a body of water): exhibiting stratification.

5Electricity. Of an electrical discharge in a tube or column of rarefied gas: exhibiting a series of luminous striations separated by dark regions.

6Of a society or culture: divided into levels or classes based on social status, education, or income.

7Statistics. Designating a method of sampling in which a sample from a heterogeneous population is obtained by dividing the population into homogeneous subgroups and taking a sample from each, or a population sample obtained by this method.