Niall
In Irish, Niall was the name of a legendary king, Niall of the Nine Hostages. Among his lasting achievements are his founding the Uí Néill dynasty, which lasted into the tenth century. It's usual anglicized form is Neil, though you also see the spelling Neal. Its orgins are obscure, and scholars have speculated that Niall may derive from the Irish word nél meaning "cloud," or else come from an older Irish word meaning "vehement; passionate."
See Also: Neil