This paper is related to automatic indexing and reformu-lation of ancient dictionaries. The objective is to make easy the access to ancient printed documents from XVI to XIX century for a diversified public (historians, scien-tists, librarians, etc.). Since the facsimile mode is insuffi-cient, the aim is to look further for the use of the index-ing based on the formal structure representative of some contents in order to optimize their exploration. Starting from a first indexing experiment operated on more recent documents, the TLF (Trésor de la Langue Française: Treasure of the French Language) in the ATILF labora-tory (Nancy, France), we extended the indexing tech-nique to automatic reformulation and reedition of ancient dictionaries. However, face to the problem extent, we limited our investigations to a very specific collections of the ATILF laboratory, the Trévoux dictionary (defined later).