The word "Prussian" can be understood in a couple of ways, primarily as an adjective and a noun.
As an Adjective: "Prussian" refers to anything related to Prussia, a historical region in Europe that was part of Germany. It can describe people, culture, military, or characteristics associated with this region.
As a Noun: A "Prussian" is a person who comes from Prussia or is a German inhabitant of that area.
In summary, "Prussian" is an adjective and noun related to the historical region of Prussia and its people. It is often used in discussions about history, culture, and military practices.