Outlining a program for “historical cognitive sociolinguistics”, this contribution explores opportunities and perspectives offered by the ongoing innovative etymological dictionary of (Proto-)Romance, viz. the Dictionnaire etymologique roman (DERom). Based on the rigourous application of the comparative- reconstructionist method, the DERom not only offers a novel view of the formal and semantic development of words from (spoken) Latin to the various Romance branches, it also implies a dynamic view of the diasystem of “global Latin”. In this contribution a selective set of Proto-Romance etyma is analyzed in order to show the systemic-functional and cognitive mechanisms at work in the development, in time and space, of word forms and word meanings, as well as the role of changing social, political, and cultural contexts. The challenging goal of historical cognitive sociolinguistics is to achieve the integration of the study of categorization and cognition in general, the synchronic, historical and comparative analysis of languages, and the evolving relationship between language, culture and society.