stormr in Geir T. Zoëga(1910)A Concise Dictionary of Old Icelandic, Oxford: Clarendon Press
Etymology
From Proto-Germanic*sturmaz, whence also Old English storm, Old Saxon storm, Old High German sturm. Ultimately from Proto-Indo-European*(s)twer-, *(s)tur-(“to rotate, swirl, twirl, move around”).