A thurs is also known as a jötunn or troll. But more commonly known as a giant in modern popular culture, though the term can be misleading as a thurs isn’t necessarily larger than humans or æsir.

Stanza from the Icelandic Rune Poem

Thurs is the cause of anguish to women
and cliff-dweller
and wedded to Varðrún.

Stanza from the Norwegian Rune Poem

Thurs causes anguish to women;
misfortune makes few men cheerful.