A name shared with the saga rendition of Attila the Hun, the name holds a connotation of wrath, and it is a derivative of the term atall meaning to be fierce, savage or wild.
A pattern I have noticed, is that this is usually used as a descriptive term of the eyes. The phrase ötul auga, which meant to have piercing eyes. Certain artifacts repeat this ocular detail, such as the ones depicted here.
Due to the protective function of Þórr, this seems to be a way of warding one from the evil eye, and unfortunate weather. Similar marks and stamp patterns adorn hammers and axe pendants from Germanic and Uralic areas.
His eyes may dispel misfortune, but pray they do not fall upon you.