The exploitation of databases for lexical purposes has undergone extensive development during the first two decades of the 21st century. The methodological implications of this fruitful alliance between corpora and electronic dictionaries nonetheless deserve particular attention, the digital aspects as well as those pertaining to lexicology and metalexicography. The integration of the non-literary vocabulary of the Documents linguistiques galloromans into the database of the Dictionnaire Étymologique de l’Ancien Français (DEAFpré), currently in progress, provides an opportunity to illustrate the demands of a rigorous conception of computer-based lexicography (i. e. based on sound philological principles, ideally innovative, manual treatment of lexemes with a computer-assisted element, concentration on etymological, semantic and syntagmatic aspects). The case-study presented in this article focuses on the potential for interpretation afforded by corpus-based lexicography, its other main aim being an evaluation of the results and the cost in terms of time. The computerised system elaborated for this purpose can be extended to other projects, particularly those focusing on medieval Galloromania.