From New Latin Prūssia, a Latinization used by Peter of Dusburg of a Baltic (Old Prussian, or perhaps Lithuanian or Latvian) autonym. The Proto-Indo-European source of the name is unclear; more at Prussia.
- (chiefly historical) A geographical area on the Baltic coast of northeastern Europe.
- (historical) A Baltic country located in this area, conquered by the Teutonic Order and ultimately absorbed into Germany.
- (historical) A German province which was originally located in this area but later greatly expanded, and which was the predecessor to and a member of the German Empire; abolished as an administrative unit at the end of the Second World War.
In the Baltic languages the 'u' is long; it was also long in Middle English, but it has become short in modern English.