I hate to cite the Wiki, but here goes (and it notes the attachment to the Arabic insult is not well supported in the literature): > The most likely etymology

I hate to cite the Wiki, but here goes (and it notes the attachment to the Arabic insult is not well supported in the literature): > The most likely etymology is through the Kaffirs, an ethnic group in Sri Lanka partly descended from Bantu slaves. The earliest known reference, under the alternative spelling "caffre" is in 1888 book The Cultivated Oranges, Lemons Etc. of India and Ceylon by Emanuel Bonavia, who notes, "The plantation coolies also smear it over their feet and legs, to keep off land leeches; and therefore in Ceylon [Sri Lanka] it has got also the name of Kudalu dchi, or Leech Lime. Europeans call it Caffre Lime." Similarly, H.F. MacMillan's 1910 book A Handbook of Tropical Gardening and Planting notes, "The 'Kaffir Lime' in Ceylon." [0] [0] https://en.wikipedia.org/wiki/Kaffir_lime https://en.wikipedia.org/wiki/Kaffir_lime