- also Tar·tar (tär'tər) A member of a group of Turkic peoples primarily inhabiting Tatarstan in west-central Russia and parts of Siberia and Central Asia.
- Tartar Any of the Turkic languages of the Tatars.
- Variant of Tartar (sense 1).
- tatar A ferocious or violent person; a tartar.
[Persian Tātār, of Turkic origin.]
This is the first we're seeing of this definition #4.