Source : Webster's Revised Unabridged Dictionary (1913)

Rattlebox \Rat"tle*box`\, n.
   1. A toy that makes a rattle sound; a rattle.

   2. (Bot.)
      (a) An American herb ({Crotalaria sagittalis}), the seeds
          of which, when ripe, rattle in the inflated pod.
      (b) Any species of {Crotalaria}, a genus of
          yellow-flowered herbs, with inflated, many-seeded
          pods.

Crotalaria \Crot`a*la"ri*a\ (kr?t`?-l?"r?-? or kr?`t?-l?"r?-A),
   n. [NL. See {Crotalum}.] (Bot.)
   A genus of leguminous plants; rattlebox.

   Note: {Crotalaria juncea} furnishes the fiber called sunn or
         Bombay hemp.

Source : WordNet®

crotalaria
     n : any of various plants of the genus Crotalaria having
         inflated pods within which the seeds rattle; used for
         pasture and green-manure crops [syn: {rattlebox}]