Source : Webster's Revised Unabridged Dictionary (1913)

Madnep \Mad"nep\, n. (Bot.)
   The masterwort ({Peucedanum Ostruthium}).

Source : WordNet®

madnep
     n : biennial weed in Europe and America having large pinnate
         leaves and yellow flowers and a bitter and somewhat
         poisonous root; the ancestor of cultivated parsnip [syn:
         {wild parsnip}]