In the history of technology, the modern engineer emerges only gradually. This article examines the figure of the architect–engineer from the antiquity to the XIX century. In particular, this work analyses the etymology of the term engineer to explain the evolution of its functions in different historical contexts. So, the linguistic evolution of the word engineer allows us to understand the dynamics of the development of this particular figure, whose definition, over the centuries, evolves from its special innate qualities to its specific tasks.