It is located in present-day Thanh Hóa Province, Vietnam.
Michel Ferlus (2012) and Frédéric Pain (2020) propose that 九真 Old Chinese *kuˀ-cin transcribed *k.cin, a local autonym which is reflected in Puoc ksiːŋ muːl & Thavung ktiːŋ² meaning "human being, people".
Both ksiːŋ and ktiːŋ² are from Proto-Vietic *kciːŋ, which consists of prefix *k- and root *ciɲ (“leg, foot”); thus, "human beings" are "(those who are) on foot", "those who stand on their feet.
"[1][2] Pain further suggests that "Cửu Chân might therefore have been inhabited by some ancestors of the Southern Vietic Thavung - Aheu.
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