Summary : The linguistic terminology used in Gustave Guillaume's theory, the psychomechanics of language, is notoriously complex. Its formation was historically determined by various parameters, such as the dialectics of continuity and discontinuity in relation to Saussure; the desire to reject abstract logic in favour of a dynamic mentalism sited in the speaking subject; the varying connections with psychology and the neurosciences; the evolution of the author's discourse from a realistic materialism to an increasingly abstract model. Out of this context stems a rather contrasted heritage: a specific metalanguage whose legitimacy is constantly being renegociated, all the more so as it has a bearing on the uncommon way of using more traditional terminology; this heterogeneity is reflected as much by the discourse of guillaumean, neo-Guillaumean and trans-Guillaumean present-day linguists as by the mere existence of several terminological dictionaries for this theory, featuring contrasting terminographical options.