Where does “مهدی‌قلی” come from?

مهدی‌قلی (Chagatai) comes from Chagatai قل, from Proto-Turkic kül — ash.

Ancestry of “مهدی‌قلی”, step by step

StepLanguageWordMeaning
1Chagataiقلslave
2Proto-Turkickülash
Every word from Proto-Turkic kül →Every word from Chagatai قل →