An Etymological Dictionary of the German Language/Annotated/rügen
rügen, verb, ‘to denounce, censure, reprove,’ from Middle High German rüegen, Old High German ruogen, ‘to accuse, charge with, blame,’ for an earlier wrogjan; compare Gothic wrôhjan, Old Saxon wrôgjan, Anglo-Saxon wrêgan, ‘to accuse, charge with.’ Allied to Modern High German Rüge, ‘censure, blame, crime,’ Middle High German rüege, Gothic wrôhs, ‘accusation,’ Old Saxon wrôht, ‘strife,’ Anglo-Saxon wrôht, ‘accusation, strife, crime.’ The Gothic forms with h compared with the g in the other terms point to Aryan k, which was the cause of the grammatical change of h to g. An Aryan root wrôk, wrâk, has not yet been discovered.