Sindarin
Sindarin is a fictional language devised by J. R. R. Tolkien for use in his secondary world known as Arda. Sindarin is one of the many languages spoken by the immortal Elves, called the Eledhrim [ˈɛlɛðrim] or Edhellim [ɛˈðɛllim] in Sindarin. The word Sindarin is itself a Quenya form. The only known Sindarin word for this language is Eglathrin, a word probably only used in the First Age (see Eglath).
Called in English "Grey-elvish" or "Grey-elven", it was the language of the Sindarin 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.