The study develops theoretical, methodological and empirical foundations for a theory of meaning that understands linguistic innovation and discursive dynamics not as a special case, but as a normal case. Through the integration of systemic and action-theoretical aspects, discourses can be described as places of meaning change. At the center of the analysis are metaphorical patterns as discourse semantic units. The case study on the discourse object virus shows that relatively stable protometaphors are repeatedly differentiated into innovative settings: In addition to the analysis of the metaphor inventories of virus as image recipient (e.g. fight against viruses), the documentation of transdiscursive drifts of the lexeme takes place, which lead to the fact that virus in many contexts (in newspaper articles, in Bundestag minutes and in print advertisements) also functions as image donor (e.g. virus of corruption). The analysis of multicodal metaphors plausibilises the discourse sensitivity of images in print advertisements and leads to the postulate of a multicodal extension of discourse analyses. On a methodological level, the study evaluates the possibilities of using existing online text databases to pursue discourse-analytical questions.