Turkmen · proper noun, noun, adjective1
The current majority view for the etymology of the ethnonym Türkmen or Turcoman is that it comes from Türk and the Turkic emphasizing suffix -men, meaning "'most Turkish of the Turks' or 'pure-blooded Turks.'" A folk etymology, dating back to the Middle Ages and found in al-Biruni and Mahmud al-Kashgari, instead derives the suffix -men from the Persian suffix -mānind, with the resulting word meaning "like a Turk". While formerly the dominant etymology in modern scholarship, this mixed Turkic-Persian derivation is now viewed as incorrect.
Turkmen · noun2
Treated as a plural of the deprecated term Turkman, influenced by English man, plural men.
Etymology from Wiktionary, CC BY-SA 4.0.