Þri-réðre

According to the Old English Dictionary:

þri-réðre

adj. Having three banks of oars; used substantively trireme :-- Ðá næfde hé má scipa ðonne án; ðæt wæs ðeáh þreréþre, Bt, 38, 1; Fox 194, 10. Þrieréþre ceól, Met. 26, 27. Án C. ðara miclena þrieréðrena centum triremes, Ors. 3, 1; Swt. 96, 27: 5, 13; Swt. 246, 6. [O. H. Ger. dri-ruodri.] þri-reðre