Jones (1978:11) derives the word from Persian bāzū However, the form bāzū is marked with an asterisk, to indicate his doubt that this is indeed the source word. The meaning of bāzū is ‘The arm, or the upper part of it; the cloth wrapped round the middle whilst bathing’. The semantic connection to ‘shirt, clothing’ is tenuous. Cognates of baju occur in Sundanese and in Javanese (including Old Javanese, where Persian influence is negligible or nonexistant). There is also a cognate in Kualan, a language of Borneo, in the form bojuh (with the same meaning). The vowel of the first syllable, as well as the final -h, both argue against it being a loanword, and for it being a retention. Therefore I conclude that baju is most probably not a loanword.
