This communication is concerned with theoretical aspects of NLP, and with some ‘epistemological impediments ’ [1] to the development of Arabic generation and recognition programs or lexical databases. The discussion focuses on the methodological approach underlying the elaboration of specifications associated to the entries of an Arabic lexical database, in relation with the DIINAR.1 Arabic Language database and the DIINAR-MBC Euro-Mediterranean project1. Such specifications consist of morpho-semantic as well as syntactico-semantic features. Semantic aspects belong to the field of finite semantics. A definition of that field will be given in connection with the notion of ambiguity, which is revisited here in the context of formal linguistics and a cognitive approach of computational linguistics.