Source : Webster's Revised Unabridged Dictionary (1913)

Felwort \Fel"wort`\, n. [Probably a corruption of fieldwort.]
   (Bot.)
   A European herb ({Swertia perennis}) of the Gentian family.

Source : WordNet®

felwort
     n : gentian of Europe and China having creamy white flowers with
         fringed corollas [syn: {gentianella amarella}]