Irridentism is a term used to describe the political ideology which seeks to reclaim territories that were once under their control. Synonyms for this word include expansionism, nationalism, and territorialism. Expansionism refers to the policy of expanding the territory or influence of a country or group of people. Nationalism focuses on the promotion of a particular nation's interests, especially to the exclusion or detriment of others. Territorialism emphasizes the importance of territorial expansion and control. In essence, these synonyms all encapsulate the desire for increased power, control, and territorial influence, often at the expense of other nations or groups of people.