'Thorntail' definitions:

Definition of 'Thorntail'

From: GCIDE

Thorntail \Thorn"tail`\, n. (Zool.) 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. [1913 Webster]