At a time of widening political divides and the return of war to Europe, Europeans urgently need to clarify the changing uses and misuses of words. By enquiring into historical semantics on a European scale and developing easily accessible material on key contested notions in several European languages ("populism", "war", "self-determination", etc), LexiECO aims to focus on key semantic issues underlying domestic and international debates and thus to help us better understand European diversity.