'Frederick I' definitions:

Definition of 'Frederick I'

(from WordNet)
noun
Son of Frederick William who in 1701 became the first king of Prussia (1657-1713)
noun
Holy Roman Emperor from 1152 to 1190; conceded supremacy to the pope; drowned leading the Third Crusade (1123-1190) [syn: Frederick I, Frederick Barbarossa, Barbarossa]