Tamarinds are fruit-bearing trees indigenous to Africa, but they've been around in south Asia and Oceania for a really long time as well. That's why Arabic traders mistakenly called it tamar hindi, meaning "date of India" (date also being the fruit tree type, although not even in the same order as tamarinds). That was borrowed into Latin as tamarindus, which became Old French tamarinde, which in the mid-sixteenth century finally developed into English tamarind and alternate spellings like thamarynde or tamarine that died out. Arabic tamar comes from a similar-sounding Proto-Semitic root with the same meaning and hindi derives from Sanskrit sindhu, meaning "river". Finally, that, through Proto-Indo-Aryan and Proto-Indo-Iranian, is eventually reconstructed to PIE kiesd, "to go away".
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd