- an abstract place usually conceived as having depth
"a good actor communicates on several levels"
"a simile has at least two layers of meaning"
"the mind functions on many strata simultaneously"

- one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism)

1. A bed of earth or rock of one kind, formed by natural causes, and consisting usually of a series of layers, which form a rock as it lies between beds of other kinds. Also used figuratively.

2. A bed or layer artificially made; a course.