Where does “테니시” come from?

테니시 (Korean) comes from English Tennessee, from Cherokee ᏔᎾᏏ — river.

Ancestry of “테니시”, step by step

Step	Language	Word	Meaning
1	English	Tennessee	The Tennessee warbler, Oreothlypis peregrina
2	Cherokee	ᏔᎾᏏ	river