Dwarvish

Dwarvish or Dwarven was the name for a family of languages used by dwarves. The dwarves called their own language Dethek, but most other races used that term to refer to the runic alphabet in which the language was written.
  Although the language in its pure form and exclusive vocabulary had fallen somewhat in disuse by the mid‒6th century WME, Dwarvish was still found all over Batia inscribed into weapons, buildings and mystical items.

The language followed dwarves all over Batia and beyond, making it an extremely widespread language. Communities and races that had been separated for some time evolved their own dialects.