Pahlavi or Pahlevi denotes a particular and exclusively written form of various Middle Iranian languages. The essential characteristics of Pahlavi are

• the use of a specific Aramaic-derived script, the Pahlavi script;
• the high incidence of Aramaic words used as heterograms (called hozwarishn, "archaisms").

Pahlavi compositions have been found for the dialects/ethnolects of Parthia, Persis, Sogdiana, Scythia, and Khotan. Independent of the variant for which the Pahlavi system was used, the written form of that language only qualifies as Pahlavi when it has the characteristics noted above.