This article explores the cognitive function of terminological variation, specifically its contribution to the construction and transfer of specialized knowledge in texts. For that purpose, explicit term variation introduced by equivalence markers was analysed in a corpus of 300 texts about lexicography written in Brasilian Portuguese. A cognitive semantic analysis was carried out in two steps: first, a description of the conceptual specification patterns (Kageura 2002) of variants allowed us to identify how different viewpoints on the concepts are provided by terminological variation. Second, variants were classified according to the degree of semantic distance from the base term (Fernández-Silva 2016) in order to quantify the informativity degree of term variation. Results showed that term variation reflects the multidimensionality of conceptual structuring, where different perspectives on the same concept cohabitate in texts. Furthermore, 85% of term variants provide additional information on the concept, specifically about its internal features and the relationships that it establishes with other concepts within the field. In conclusion, this study supports the thesis that term variation can be used as a cognitive device. It makes it possible to depict different aspects of the conceptual content and, in turn, contributes to a richer representation of knowledge in texts.