Tolkien gave us this term. It was the old word for dwarf, or what the dwarves called themselves.
It is so much more of a strong word than dwarf. I think it more deeply represents the stout, deep-earth nature of the bearded miners.
And ignore that "Snow White and the 7 Dwarves" crap. For a real dwarven story try the novel "Dragon Doom" by Dennis L. McKiernan. Now that is a good story rich in well crafted dwarves.