Source : Webster's Revised Unabridged Dictionary (1913)

Thornbill \Thorn"bill`\, n. (Zo["o]l.)
   Any one of several species of small, brilliantly colored
   American birds of the genus {Rhamphomicron}. They have a
   long, slender, sharp bill, and feed upon honey, insects, and
   the juice of the sugar cane.

Source : WordNet®

thornbill
     n : any of various South American hummingbirds with a sharp
         pointed bill