stratum (plural stratums)
- One of several parallel horizontal layers of material arranged one on top of another.
- Synonyms: tier
- (geology) A layer of sedimentary rock having approximately the same composition throughout.
- Synonyms: bed, layer
- Coordinate term: seam#English|seam
- Any of the regions of the atmosphere, such as the stratosphere, that occur as layers.
- (biology) A layer of tissue.
- A class of society composed of people with similar social, cultural, or economic status.
- (ecology) A layer of vegetation, usually of similar height.
- (computing) The level of accuracy of a computer's clock, relative to others on the network.