Tajiks, an ethnic group living in Afghanistan, Tajikistan, Uzbekistan, Iran, Pakistan, and western China.

Tajik language, the official language of Tajikistan; Persian written in Cyrillic.

note: To distinguish between the nationality and the ethnicity, some sources (such as CIA factbook) use the adjective Tajikistani for the citizens of Tajikistan. Tajik is occasionally written as Tadzhik or Tadjik, a transcription of the Russian spelling.

The Sarikoli language, spoken by Tajiks in China and officially referred to as the Tajik language there.

The Arabic-schooled, ethnically Persian administrative caste of the Turco-Persian society.