skir·ret 
(skûrĭt)
(skûrĭt)n.
An eastern Asian plant (Sium sisarum) in the parsley family, having a cluster of tuberous, sweetish, edible roots.
[Middle English skirwhit, alteration (influenced by skir, pure, bright and white, white) of Old French eschervi, probably from Arabic karawyā, caraway, from Greek karō.]