What does "parsnip" mean?

Parsnip: The aromatic and edible spindle-shaped root of the cultivated form of the Pastinaca sativa, a biennial umbelliferous plant which is very poisonous in its wild state; also, the plant itself. Cow parsnip. See Cow parsnip. -- Meadow parsnip, the European cow parsnip. -- Poison parsnip, the wild stock of the parsnip. -- Water parsnip, any plant of the umbelliferous genus Sium, the species of which are poisonous.