A lot of people just assume that the word parsnip is a combination of parsley and turnip. Well, not really. As parsnip developed into existence from the Old French word pasnaie, the -nip ending was indeed added by influence of turnip, but the rest was unique. Anyway, pasnaie (which could also be a euphemism for "penis") comes from Latin pastinaca, which meant both "parsnip" and "carrot". This in turn derives from pastinum, which meant something like "two-pronged fork or spade", because they have a similar shape. Although this has an unknown etymology officially, I'm guessing it comes from a word for "dig" (based on a connection to pastinare, with that meaning), possibly because of the "spade" connection. It might not even be Indo-European; just some wild guesses. Although it was borrowed in the 1300s, the word parsnip has had relatively constant usage since the late 1700s.
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