Old Norse hinn almáttki áss = 'the almighty god' (see also Æsir)
Unnamed god in an oath formula in Ólafs saga Tryggvasonar and in the Landnámabók:
"Hjálpi mér svá Freyr ok Njǫrðr ok hinn almáttki áss" = 'So help me Freyr and Njǫrðr and the almighty As'. The oath is made on a temple ring and the three gods are called upon to witness the oath. There are some theories who this unnamed god may be: Ullr, Óðinn or Þórr.