·noun The ruddy duck.
II. Spinetail ·noun Any one or several species of swifts of the genus Acanthylis, or Chaetura, and allied genera, in which the shafts of the tail feathers terminate in rigid spines.
III. Spinetail ·noun Any one of several species of South American and Central American clamatorial birds belonging to Synallaxis and allied genera of the family Dendrocolaptidae. They are allied to the ovenbirds.