Where does “Chekiangese” come from?

Chekiangese (English) comes from English ese, from Mexican Spanish ese, from Latin ipse, from Proto-Italic *e(s)peso — himself, herself, itself.

Ancestry of “Chekiangese”, step by step

Chekiangese traces back through two separate lines of ancestry.

via English ese

StepLanguageWordMeaning
1Englishesedude, man
2Mexican SpanisheseThe name of the Latin-script letter S; that;...
3Latinipsehimself, herself, itself, the very, the actual;...
4Proto-Italic*e(s)pesohimself, herself, itself

via English Chekiang

StepLanguageWordMeaning
1EnglishChekiang
2Chinese Mandarin浙江
Every word from Proto-Italic *e(s)pesoEvery word from Latin ipseEvery word from Mexican Spanish ese