The fruit and its leaves, known botanically as Citrus hystrix, are native to Sri Lanka and are also found in Mauritius and South East Asia, where the plant is known as Makrut.
It is thought it became known as kaffir lime in reference to the Kaffirs ethnic group in Sri Lanka who traditionally smeared it on their legs and feet to ward off leeches.
However, the word kaffir also became a term for a non-Muslim, or disbeliever, in Arabic, which was in turn applied to sub-saharan Africans who did not practice Islam. From here it became a racist insult used by South African whites against the country’s indigenous population.
And of course we do not use the word any more because we’re aware.
But do Arabs?
Would, for example, Nesrine Malik, that Sudanese Arab, use the word to refer to sub-Saharan non-believers?