Save Gender Masculine Usage Ancient Scandinavian [1] Expand LinksMeaning & History Derived from the Old Norse elements Þórr (see THOR) and fastr "firm". Family Tree·DetailsRelated Names DiminutiveTófiOther Languages & CulturesTue(Danish) Categories strength Sources & References Viking Answer Lady Webpage, available from https://www.vikinganswerlady.com/ONNames.shtml. Entry updated February 4, 2020 ·