The word "jackfruit" comes from Portuguese jaca, which in turn is derived from the Malayalam language term chakka (Malayalam chakka pazham). When the Portuguese arrived in India at Kozhikode (Calicut) on the Malabar Coast (Kerala) in 1498, the Malayalam name chakka was recorded by Hendrik van Rheede (1678–1703) in the Hortus Malabaricus, vol. iii in Latin. Henry Yule translated the book in Jordanus Catalani's (f. 1321–1330) Mirabilia descripta: the wonders of the East.
The common English name "jackfruit" was used by physician and naturalist Garcia de Orta in his 1563 book Colóquios dos simples e drogas da India. Centuries later, botanist Ralph Randles Stewart suggested it was named after William Jack (1795–1822), a Scottish botanist who worked for the East India Company in Bengal, Sumatra, and Malaysia.
Source : https://en.wikipedia.org/wiki/Jackfruit