In the Ulster Cycle of Irish mythology, the Caladbolg, "hard-belly", or Caladcholg, "hard-blade", was the sword of Fergus mac Róich. During the Táin Bó Cuailnge, when Fergus was prevented from killing Conchobar mac Nessa with it, he redirected his fury and cut the tops off three hills.
It is thought to be a source or analogue of King Arthur's sword Excalibur, which in early Welsh is called Caledfwlch.
The word was also used as the name of Tidus' celestial weapon in Final Fantasy X
