Where does “ترکمن” come from?

ترکمن (Persian) comes from Old Turkic 𐱅𐰇𐰼𐰜, from Proto-Turkic *tür(ü)k.

Ancestry of “ترکمن”, step by step

Step	Language	Word	Meaning
1	Old Turkic	𐱅𐰇𐰼𐰜	—
2	Proto-Turkic	*tür(ü)k	—