What is "alviss"

Alvíss ("All-Wise") was a dwarf in Norse mythology.

Thor's daughter, Þrúðr, was promised in marriage to Alvíss. Thor was unhappy with the match however, so he devised a plan. He told Alvíss that, because of his small height, he had to prove his wisdom. Alvíss agreed, but Thor made his tests last until dawn, when Alviss, because he was a dwarf, was turned to stone on being exposed to the sunlight.