One way to hold Cajun: start with a group of families. They were French speakers from Acadia in eastern Canada, and they ended up in the warm, wet south of Louisiana. Their name travelled with them and wore down in the mouth — Acadien, Cadien, Cajun. Everything else the word touches is something those families carry: the French they still speak, the music they dance to, the pepper in their cooking. So the word is really one word: a people, and then whatever wears their name.
An Anglicisation of Acadian French Cadien, itself a shortened Acadien ('Acadian'), reflecting the Acadian dialect turning /dj/ into a j-like sound. The people's name is literally the place their families came from, worn short.
這是阿卡迪亞法語 Cadien 進入英文後的拼法，而 Cadien 又是 Acadien（阿卡迪亞人）掉了開頭的樣子；阿卡迪亞方言把 d 加 i 的音唸成接近英文 j 的音，所以寫成 Cajun。族群的名字，其實就是他們家族來的那個地方唸短了。
Wiktionary etymology_text supplied in evidence packet (source_ref kaikki:3f6f69a190036ae4:1020786501:4274)
Two branches
那群人
這一族就是核心畫面本身：名字先屬於人，其他用法都是從人身上借出去的。
noun · B2
A person from Louisiana, in the southern United States, whose family came from Acadia, a French-speaking part of eastern Canada. Cajuns are largely French-speaking and Catholic, and they have their own cooking and their own music.
卡津人
掛著他們名字的東西：語言、味道、音樂
族群名一旦放到別的名詞前面，就等於在說「這是那群人的」；跟著出去的東西越有名，那個用法就越獨立，最後連食物和音樂都能自己站著。
noun · B2
A lively kind of folk dance music played by the Cajun people of Louisiana.
卡津音樂