Alcir S. answered • 05/17/20
Native Portuguese Speaker with 10+ years of Professional Translation
According to an Etymology (study of the history of words) Dictionary, the word "Mandarin" originated in 1580s: "via Portuguese mandarim or older Dutch mandorijn from Malay (Austronesian) mantri, from Hindi mantri "councilor, minister of state," from Sanskrit mantri, nominative of mantrin- "adviser," from mantra "counsel," from PIE root *men- (1) "to think." Form influenced in Portuguese by mandar "to command, order"." The word “Mandarin” refers to Chinese Officials during the Portuguese exploration of Asia. Thus, this word derives from the Portuguese language to describe a Chinese noun.
Source: https://www.etymonline.com/word/mandarin#etymonline_v_6779
