Dwalin

It is unusual for a Dwarf to live longer than about 250 years, so at 340, Dwalin seems to have lived almost a century longer than almost any other his kind. This hints at an error, but Christopher Tolkien notes (in The History of Middle-earth volume XII) that Dwalin's date of death, given as as '3112' in years of the Third Age, remained consistent over several drafts. However, there is a very indefinite suggestion in an early document that his age at death should have been 251, in which case he would have died in the second year of the Fourth Age.

To be precise, Dwalin was the great-grandson of Borin, one of the refounders of the Dwarf-kingdom of Erebor, and Borin was the younger son of King Náin II.

At least, in the Norse poem Völuspá, the source of many of Tolkien's Dwarf-names, this seems to be the meaning.