Any of various South American hummingbirds with a sharp pointed bill

Wiktionary Word definitions in Wiktionary
n. Any of the passerine birds of the genus ''Acanthiza''.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
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.

WordNet Word definitions in WordNet
n. any of various South American hummingbirds with a sharp pointed bill