There are many kinds of persimmons, from all over the world. There was already a word for them (diospyros) when new colonists in the Americas encountered a new type in Virginia, but they borrowed a Powhatan word to classify it: pichamins, which also took the form of pushemins, and pasimenan, all of which described the fruit/flower and had a literal meaning of "dry fruit". Powhatan is part of the Algonquian family of languages, and the -imen- part of the word seems to go back to a common Proto-Algonquian root, imin, which meant "fruit" or "berry", possibly going all the way back to Proto-Algic mene, also "berry" (Proto-Algic is a little-researched and hypothesized tongue encompassing Algonquian and several lesser families). The pas- prefix and -an suffix like as not took a similar route. Usage of persimmon peaked around 1940.
Adam Aleksic, a leading contender for valedictorian of his high school, is a 208-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and just won an essay contest on linguistics!
The Etymology Nerd