Another round vegetable, pumpkin also dates all the way back to PIE. In those halcyon days of yore, pumpkin meant "to cook" and was spelled pekw (also the forefather of today's word cook). This then went to Ancient Greek as peptein "to cook". This eventually gave way to another Greek word, pepon, or "melon", supposedly because this cucurbit (a word meaning "of the melon family") was "cooked by the sun". The Greeks then happily used this word for about five hundred more years until its history was rudely hijacked by those darn Romans. Greek peopon therefore became peponem, which after Latin disintigrated, became French pompon, still with the definiton of "melon" and possibly the origin of a cheerleader's pompom. When this diffused into English as pumpion, it meant "melon or pumpkin" and as it became pumpkin, its definiton solidified as well. The word pumpkin, which was finalized in the seventeenth century, is also the father of many colloqualisms and expressions in our language. Pumpkin as a term of endearment probably meant from "round, cute child", pumpkin-head suggested that you had "goop for brains" and pumpkin pie developed as the delicacy did. Lastly, I just would like to recap and point out that when you say you're "cooking pumpkin pie" you're actually "cooking cooking pie."
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