Western reference works regard the architectural term pagoda as being of uncertain origin, but an overlooked etymology proposed by Liang Sicheng convincingly solves the mystery: The word is Chinese, with the literal meaning “eight” (pa) “cornered” (ko) “tower” (La). Liang Sicheng, who pioneered the serious study of classical Chinese architecture, pointed out:
‘The octagonal pagoda, which first appeared in the Tomb Pagoda of Ching-tsang in 746, was the first “pa-go-da” in the real sense of the term.’
This 746 date is of course centuries before the first appearance of pagoda in a European language, viz. 1516 in Portuguese, so the chronology presents no problems.
In a speculative vein D. R. Tien adds that a specific pagoda constructed later (between 1597 and 1600) probably played an important role in helping the term to become entrenched in English and other European languages: the Pazhouta, standing in the Pearl River Estuary.
Also, besides the architectural term pagoda in China, there are similar sounding words used elsewhere (pa-god\ pagotha, pagoda, etc.) pertaining to pagan deities or idols - very possibly homonymous with the Chinese architectural word but not its source.
Available at: http://works.bepress.com/gerald-cohen/5/