Source : Webster's Revised Unabridged Dictionary (1913)

Amorpha \A*mor"pha\, n.; pl. {Amorphas}. [Gr. ? shapeless.]
   (Bot.)
   A genus of leguminous shrubs, having long clusters of purple
   flowers; false or bastard indigo. --Longfellow.

Source : WordNet®

amorpha
     n : any plant of the genus Amorpha having odd-pinnate leaves and
         purplish spicate flowers