The Collaborative International Dictionary of English v.0.48:

Elecampane \El`e*cam*pane"\, n. [F. ['e]nulecampane, NL. inula
   campana; L. inula elecampane + LL. campana a bell; cf. G.
   glockenwurz, i. e., "bellwort."]
   1. (Bot.) A large, coarse herb (Inula Helenium), with
      composite yellow flowers. The root, which has a pungent
      taste, is used as a tonic, and was formerly of much repute
      as a stomachic.
      [1913 Webster]

   2. A sweetmeat made from the root of the plant.
      [1913 Webster]

WordNet (r) 3.0 (2006):

elecampane
    n 1: tall coarse Eurasian herb having daisylike yellow flowers
         with narrow petals whose rhizomatous roots are used
         medicinally [syn: elecampane, Inula helenium]