After the first work on machine-readable dictionaries (MRDs) in the seventies, and with the recent development of the concept of a lexical database (LDB) in which interaction, flexibility and multidimensionality can be achieved, but everything must be explicitly stated in advance, a new possibility which is now emerging is that of a procedural exploitation of the full range of semantic information implicitly contained in MRDs. The dictionary is considered in this framework as a primary source of basic general knowledge. In the paper we describe a project to develop a system which has word-sense acquisition from information contained in computerized dictionaries and knowledge organization as its main objectives. The approach consists in a discovery procedure technique operating on natural language definitions, which is recursively applied and refined. We start from free-text definitions, in natural language linear form, analyzing and converting them into informationally equivalent structured forms. This new approach, which aims at reorganizing free text into elaborately structured information, could be called the Lexical Knowledge Base (LKB) approach.