Since the 1990s, the analysis of variation in specialized languages has been developing under the impulse of new theories of terminology, as well as its reconciliation with linguistics and corpus-based approaches. Despite the importance of existing research, several facets of term variation remain to be explored. In our communication, we propose in particular to feed the reflection on the needs and possibilities of analyzing several types of dialectal variation (Freixa 2006, Fernandez-Silva & Freixa 2017), simultaneously present in specialized corpora. Indeed, as several authors point out (e.g. Gadet 2003: 119-120), the different types of dialectal variation are closely linked and it is essential to take these links into account in the analysis of their "linguistic manifestations". In the field of specialized language, our proposal arises from several observations, in different applied demands encountered in recent years, in work contexts subject to multiple variations: - First, we propose to focus on university pedagogy, a rapidly evolving domain, where several communities of experts work together (prototypically researchers and academic advisors), in different French-speaking countries (Picton & Dury 2017). This context illustrates the dynamics between three types of dialectal variation that coexist in specialized corpora: diachrony, diatopy and diastraty; - Second, we propose to discuss the analysis of determinologisation, in particle physics. Determinologisation is here considered as a process of passage of terms in different genres and degrees of speciality, through time (Picton et al. 2021). This context illustrates the particular link between diachrony and diastraty, a type of variation which necessarily manifests itself over time (ibidem). Our analyses, based on Textual Terminology approaches, rely on the systematic observation of different types of linguistic clues and on discussions with domain-field experts. We thus trace and analyze the variants of different concepts in two specialized corpora, qualified as “multicomparable”, in each of the two selected domains. We propose more specifically to discuss the phenomena at stake regarding dialectal variation in these domains, the complementarity of the variations under study and how these contexts offer new paths for reflection on term variation. We then sharpen our focus on methodological challenges regarding corpus- and tool-based approaches in Textual Terminology when analyzing “multi-comparable” corpora.