Anthriscus cerefolium

from The Collaborative International Dictionary of English v.0.48

Chervil \Cher"vil\, n. [AS. cerfille, fr. L. caerefolium,
   chaerephyllum, Gr. ?; ? to rejoice + ? leaf.] (Bot.)
   A plant ({Anthriscus cerefolium}) with pinnately divided
   aromatic leaves, of which several curled varieties are used
   in soups and salads.
   [1913 Webster]