Gnomish

For a race is known for their ingenuity, constant need to invent stuff, they still use the same language they did millennia ago. Their creator, Father of the Forge made the Khazadun language and instead of using it, the gnomes of the First Age, The Titan War invented their own. During the Second Age, Godswar it was widespread among the gnome population and even in the Fifth Age, Current Age not many things changed, only new words and phrases were added. As such, it is the only language used by mortals that was invented by mortals in the First Age and they don't even have a special name for it.