This chapter studies the evolution of the terms and expressions used to describe the Russian-Ukrainian armed conflict from its onset in 2014 to the full-scale Russian invasion of Ukraine in 2022. Drawing on a comparative analysis of official reports and the websites of international organisations, the first stage of the study examines the evolution of the terminology used by these organisations and how it is influenced by the Minsk agreements. The second stage explores how this institutional terminology is recontextualized in a corpus of Swiss newspapers. The findings show that the lexicon of the conflict evolved alongside its development and emphasise the interaction between institutional discourse and media narratives. The Russian invasion of Ukraine in 2022 marked a shift both in the development of the international armed conflict itself and in the language used to refer to it, as it led to the obsolescence of the Minsk agreements, followed by a shift towards a lexicon more closely aligned with International Humanitarian Law. These dynamic lexical adjustments present potential challenges for language professionals, who must understand not only the terms but also their broader diplomatic, rhetorical, political, and legal implications and overtones.