Ontological variation and sense extension in proper names.

The lexical coverage of the semantic database ItalWordNet has been extended by adding to the first nucleus of nouns and verbs, a set of adjectives and adverbs and also a set of Proper Names (PNs). Particular cases of polysemy were found in codifying PNs. Sense variation in PNs was verified in linguistic resources and new semantic relations were created in order to represent the sense extension phenomenon in the database. The relationship between the PNs present in IWN and the ontological classification of their belonging classes was highlighted: correspondence between sense variations and ontological variations was examined and the reference to the ontological structure of IWN was of help in recognizing many cases of PNs sense extension.