The phenomenon of mamluks of Mongol origin during the early Mamluk period (roughly 648–741/1250–1341) has been studied by several scholars, but mamluks of Mongol origin during later periods have hardly received scholarly attention. This must be mostly due to the decline in the number of Mongol mamluks after the early period, but it is also due to terminological difficulties. The two main labels in Mamluk sources that were, in all likelihood, used in the early period to refer exclusively or largely to mamluks of Mongol origin (or mamluks who arrived from Mongol Central Asia or were annexed to the Mongol Khanates of the East)—namely Mughul and Tatar—would later fall out of use in this context (in the case of Mughul) or gradually shift semantically (as happened with Tatar). This article makes a modest contribution to the discussion of mamluks of Mongol origin (or mamluks from [Timurid] Central Asia) during the later period of the Mamluk Sultanate by examining the term Turkī khāliṣ (“a pure Turk”) in Mamluk sources. I survey the few usages of the expression Turkī khāliṣ that are relevant for the Mamluk period and show that Turkī khāliṣ indeed denoted “Mongol” or “of (Timurid) Central Asia,” starting at some point during the first half of the ninth/fifteenth century. Next, I offer context and an explanation for the usage of the term in accordance with this meaning.