Webster’s Revised Unabridged Dictionary · 1913
Rat-tail
Rat′-tail′ (răt′tāl′), a. Like a rat's tail in form; as, a rat-tail file, which is round, slender, and tapering. See Illust. of File.
Rat′-tail′, n. 1. (Far.) pl. An excrescence growing from the pastern to the middle of the shank of a horse.
2. (Zoöl.) (a) The California chimæra. See Chimæra. (b) Any fish of the genus Macrurus. See Grenadier, 2.