trundletail

[truhn-dl-teyl]

noun Archaic.

Origin of trundletail

First recorded in 1480–90; trundle + tail¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

The trundletail was a species of dog in little estimation, I believe; it is mentioned in the "Lear" of Shakespeare.
A Select Collection of Old English Plays, Volume 12 (of 15)
Robert Dodsley