Spine"tail` (?), n. (Zoöl.) (a) Any one or several species of swifts of the genus Acanthylis, or Chætura, and allied genera, in which the shafts of the tail feathers terminate in rigid spines. (b) Any one of several species of South American and Central American clamatorial birds belonging to Synallaxis and allied genera of the family Dendrocolaptidæ. They are allied to the ovenbirds. (c) The ruddy duck. [Local, U.S.]

Spine"tail` (?), n. (Zoöl.) (a) Any one or several species of swifts of the genus Acanthylis, or Chætura, and allied genera, in which the shafts of the tail feathers terminate in rigid spines. (b) Any one of several species of South American and Central American clamatorial birds belonging to Synallaxis and allied genera of the family Dendrocolaptidæ. They are allied to the ovenbirds. (c) The ruddy duck. [Local, U.S.]