Wave model
THE THEORY THAT LIGHT IS DUE TO VIBRATIONS OR UNDULATIONS AS THE MEDIUM THROUGH WHICH IT IS TRANSMITTED FROM ITS SOURCE IN A LUMINOUS BODY
Wave theory; Wave model (linguistics); Wave-model
In historical linguistics, the wave model or wave theory (German Wellentheorie) is a model of language change in which a new language feature (innovation) or a new combination of language features spreads from its region of origin, affecting a gradually expanding cluster of dialects. Dialect diffusion spreads from a given point of contact like waves on the water.