divergence (n.)

A term used in SOCIOLINGUISTICS to refer to a process of DIALECT change in which the dialects become less like each other (or diverge). This process (sometimes called ‘dialectalization’) is only likely to happen in the absence of geographical and social links between populations within a SPEECH community, lines of communication thereby being few or difficult, and a STANDARD dialect probably being non-existent. The opposite effect is known as CONVERGENCE. ‘Divergence’ also has a currency in HISTORICAL linguistic studies, referring to the splitting of a FORM into two CONTRASTIVE UNITS.