Cognitive Interpretation of Polysemy

Polysemy is a prevailing phenomenon in languages.It means that a word has many differences in meanings but coherences in semantic network.Polysemy is discussed from the perspective of prototype,cognitive metaphor and metonymy,discovering that a polysemic word constitutes a semantic category with its primary meaning as the prototype while other members in that category are derived from it,exhibiting a family resemblance and degrees of typicality as well,and that the extension of word meaning is mainly achieved through metonymical thinking based upon contiguity and metaphorical thinking based upon similarity.