also: プロシャ
noun
Prussia
Historical term for the former European state. Usually written in katakana.
See also: プロイセン
プロシアは19世紀にドイツ統一の中心となった。
Prussia became the center of German unification in the 19th century.
プロイセン is the more common modern Japanese term for Prussia. プロシア is an older or alternate form.
From English 'Prussia' or possibly Dutch 'Pruisen'.