From Online Dictionary of Crystallography
Superréseau (Fr). Übergitter (Ge). Superreticolo (It). 超格子 (Ja).
A lattice L' obtained from another lattice L by adding one or more sets of nodes is called a superlattice of L. The translation subgroup T' of L' is a supergroup of the translation subgroup T of L. The unit cell of L' is smaller than the unit cell of L and is therefore called a subcell.
In chemistry and material science literature the term superlattice is often incorrectly used to indicate a superstructure.