In this paper, we will deal with some aspects concerning the representations of urban space as they are made in some selected passages from the book XV of Isidore of Seville‟s Etymologiae. In this book, Isidore exposes the main words which he employs for describing the urban space. From a grammar-based scrutiny in which we can find four principles of definition – etymology, analogy, gloss, and difference –, Isidore presents the appropriate nuances of the uerba which describe and, at the (...) same time, signifies the res of urban space: ciuitas, urbs, etc. (shrink)