In
Norse mythology, 'Þrívaldi' (anglicized as 'Thrívaldi' or 'Thrivaldi'), whose name means "thrice mighty", is a
giant killed by
Thor.
This fact is mentioned by
Snorri Sturluson in the ''
Skáldskaparmál''
(4), according to which "killer of Þrívaldi" (''"vegandi Þrívalda"'') is a ''
kenning'' for Thor. Snorri quotes one stanza by
Bragi Boddason, who calls Thor "cleaver apart of Þrívaldi's nine heads"
[1] (''"sundrkljúfr níu höfða Þrívalda"''), and another stanza by
Vetrliði Sumarliðason who praises Thor for having battered (''"lemja"'') Þrívaldi.
Þrívaldi is also listed in the
þulur.
Reference
1. Anthony Faulkes, translation of: Snorri Sturluson. ''Edda''. London: Everyman, 1995. ISBN 0-460-87616-3.