https://zh.wikipedia.org/wiki/%E5%AE%98%E8%AF%9D
\> 西方语言称官话为 mandarin，为葡萄牙人对明朝官员的称呼，最早见于16世纪初期的文献。葡萄牙人借用了马来语menteri一词，意为官员，而马来语menteri一词则源自梵文的mantrin。英语 Guan dialect 或者 Mandarin Chinese 指的也是Mandarin（朝廷官僚）使用的汉语。

英文版
\> The English word "mandarin" (from Portuguese *mandarim*, from Malay *menteri*, from Sanskrit *mantrī*, mantrin, meaning 'minister or counsellor') originally meant an official of the Ming and Qing empires.

牛津词典
https://www.oxfordlearnersdictionaries.com/us/definition/english/mandarin
\> ... (denoting a Chinese official): from Portuguese *mandarim*, via Malay from Hindi *mantrī* ‘counsellor’.