According to "The Pellissippi State Story 1974-1998," "Pellissippi" ("Pelisipi'' on early maps of Tennessee), meaning "winding waters," is the Cherokee name for the Clinch River. However, the Cherokee do not have "p" or "s" sounds in their language. Also, in Cherokee, "winding river" would be phonetically spelled "adanuteyoha geyvi" (pronounced: ah-dah-new-tay-yo-ha gey-yuh-ee).
The Decolonial Atlas shares a fascinating early map of the area labeled by Yuchi Tribal Historian Woktela D. K. Hackett. On it, the Clinch River labeled as Pellissippi, which is derived from "pelecenepi" in the Yuchi language and means "yonder drink."
Dig a little deeper into the sources linked below!