Sindarin is one of the constructed languages devised by J. R. R. Tolkien for use in his fantasy stories set in Arda, primarily in Middle-earth. Sindarin is one of the many languages spoken by the Elves.
The word Sindarin is Quenya for Grey-elven, since it was the language of the Grey Elves of Beleriand. These were Elves of the Third Clan who remained behind in Beleriand after the Great Journey. Their language became estranged from that of their kin who sailed over sea. Sindarin derives from an earlier language called Common Telerin, which evolved from Common Eldarin, the tongue of the Eldar before their divisions, e.g., those Elves who decided to follow the Vala Oromë and undertook the Great March to Valinor. Even before that the Eldar Elves spoke the original speech of all Elves, or Primitive Quendian.