Ostyak

Russian Остя́к (Ostják, “Easterner”), from Khanty āsjaχ (“people of the river Ob”).

Ostyak (plural Ostyaks)

1. (now rare) A member of any of several indigenous peoples in Siberia, Russia, including the Khanty people and the Ket people. [from 17th c.]
   • 1789, Erasmus Darwin, The Loves of the Plants, J. Johnson, page 36:

     The Ostiacks blister their skin by a fungus found on Birch-trees; and use the Agaricus officin. for Soap.

Ostyak

1. (now rare) Any of various languages of these peoples. [from 19th c.]

• Yatsko, tokays