Frisius Save Could not find Frisiorum in Logeion dictionaries. Frisiorum Proper-name adjective: masculine genitive plural, Proper-name adjective: neuter genitive plural of Frisius Frisiorum Proper-name noun: masculine genitive plural of Frisii See Frisiorum in Morpho DMLBS Frisius , inhabitant of Friesland, Frisian. s885 adfuere tum ~ii certamine simul Æthelw. IV 3 p. 45; immisit ergo Dominus omnipotens ‥ gentes crudelissimas, ‥ Wandalos cum Fresis H. Hunt. V prol. p. 139.