expansionist /ɪkˈspæn.ʃən.ɪst/adjective 1noun 1forms 3 adjective1 •Of or pertaining to expansionism.Lindberg says that current phenomena are reminiscent of the 1930s, right before the expansionist ambitions of Nazi Germany and Imperial Japan sparked a world war. — 2025 noun1 •An advocate of expansionism. formsexpansionists · more expansionist · most expansionist