Where does “シンシナティ” come from?

シンシナティ (Japanese) comes from English Cincinnati — A 7–9 or 8–10 split.

Ancestry of “シンシナティ”, step by step

Step	Language	Word	Meaning
1	English	Cincinnati	A 7–9 or 8–10 split

シンシナティ — Etymology, Origin & Word History | Etymology Explorer