An Etymological Dictionary of the German Language/Annotated/renken
renken, verb, ‘to twist, wrench,’ from Middle High German ręnken, Old High German ręnchen, ‘to turn this way and that,’ for an earlier *wrankjan (from the stem rank, ‘to dislocate,’ are derived the Romance cognates, Italian ranco, ‘lame,’ rancare, ‘to halt’). Anglo-Saxon wręnč, ‘bend, artifice,’ Anglo-Saxon wręnčan, ‘to turn,’ English wrench, substantive and verb. The corresponding verb is ringen, Teutonic wringan; the k of renken (probably for kk) compared with the g of ringen resembles the variation in bücken and biegen, lecken and Gothic bilaigôn, &c. With the pre-Teutonic root wrenk (wreng) compare Greek ῥέμβω, ‘to turn,’ ῥόμβος, ‘top.’ Compare Rank.