Source : Webster's Revised Unabridged Dictionary (1913)

Yakut \Ya*kut"\, n.
   The Turkish language of the Yakuts, a Mongolian people of
   northeastern Siberia, which is lingua franca over much of
   eastern Siberia.

Source : WordNet®

Yakut
     n 1: a member of a Turkic people of northeastern Siberia (mainly
          in the Lena river basin)
     2: the Turkic language spoken by the Yakut people