An Etymological Dictionary of the German Language/rächen
rächen, vb., ‘to revenge, avenge,’ from MidHG. rëcken, OHG. rëhhan, older *wrëhhan, ‘to revenge, obtain satisfaction for some one’; corresponding to Goth. wrikan, ‘to persecute,’ gawrikan, ‘to avenge,’ AS. wrëcan, ‘to drive out, revenge, chastisise’ E. to wreak, to which wreak is akin, Du. wreken, ‘to revenge,’ and wraak, wrake, f., ‘revenge,’ OSax. wrekan, ‘to chastise.’ The Teut. root wrek (comp. also Rache, Recke, Wrak) with the prim. meaning ‘to pursue, or rather expel, especially with the idea of punishment,’ is derived from a pre-Teut. wreg, werg. It is usually compared with Lat. urgeo, ‘I oppress,’ Sans. root vṛj, ‘to turn away,’ Gr. εἴργω, ‘enemy,’ Lith. rárgas, ‘distress’ (vàrgti, ‘to be in want’), which imply an Aryan root werg, wreg.