Quick answer
Vidar is a boy name meaning "Víðarr".
Meaning and history
From Old Norse Víðarr, which was possibly derived from víðr "wide" and herr "army, warrior". In Norse mythology Víðarr was the son of Odin and Grid. At the time of the end of the world, Ragnarök, it is said he will avenge his father's death by slaying the wolf Fenrir.
Notes and context
Usage: norwegian, swedish, norse mythology