superposition

1. The placing of one thing on top of another. (countable, uncountable)
2. The deposition of one stratum over another; the principle that in a series of sedimentary strata, the lower strata are the older. (countable, uncountable)
3. The situation in quantum mechanics where two or more quantum states are added together (superposed) to yield another valid quantum state. (countable, uncountable)

الجمع superpositions