The Collaborative International Dictionary
Thorntail
Thorntail \Thorn"tail`\, n. (Zo["o]l.) A beautiful South American humming bird ( Gouldia Popelairii), having the six outer tail feathers long, slender, and pointed. The head is ornamented with a long, pointed crest.
Wiktionary
thorntail
n. Any of various hummingbirds of the genus ''Discosura''.