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16c., parsnepe, corruption (by influence of Middle English nepe "turnip;" see neep) of Middle English passenep (late 14c.), from Old French pasnaise "parsnip," also "male member" (Modern French panais), from Latin pastinaca "parsnip, carrot," from pastinum "two-pronged fork" (related to pastinare "to dig up the ground"); so called from the shape of the root. The parsnip was considered a kind of turnip.