Prototype theory makes a crucial distinction between central and peripheral sense of words. Geeraerts explores the implications of this model for a theory of semantic change, in the first full-scale treatment of the impact of the most recent developments in lexicological theory on the study of meaning change. He identifies structural features of the development of word meanings which follow from a prototype-theoretical model of semantic structure, and incorporates these diachronic prototypicality effects into a theory of meaning change.