Frederick I

UK: /ˈfrɛdrɪk/

WordReference Random House Unabridged Dictionary of American English © 2026

Frederick I, 

1. Biographical ("Frederick Barbarossa'') 1123?–90, king of Germany 1152–90;
   king of Italy 1152–90: emperor of the Holy Roman Empire 1152–90.
2. Biographical 1194–1250, king of Sicily 1198–1212: as Frederick II, king of Germany and emperor of the Holy Roman Empire 1215–50.
3. Biographical 1657–1713, king of Prussia 1701–13 (son of Frederick William the Great Elector).

Collins Concise English Dictionary © HarperCollins Publishers::

Frederick I / ˈfrɛdrɪk/ noun

1. See Frederick Barbarossa
2. 1657–1713, first king of Prussia (1701–13); son of Frederick William