Definition of superstrate:
(n) :
A layer or stratum adjacent and parallel to another.
(n) :
(photovoltaics) The covering on the sunny side of a photovoltaic (PV) module, providing protection for the PV materials from impact and environmental degradation while allowing maximum transmission of the appropriate wavelengths of the solar spectrum.
(n) :
(physics) The sudden increase in the electrical conductivity of some metals as their temperature falls to near absolute zero.
(v) :
To arrange in parallel layers or strata.
(n) :
(linguistics) Alternative form of superstratum. [(geology) A stratum that is on top of another]