a gland opening on the back at the base of the tail in most birds that secretes an oily fluid used by the bird in preening its feathers.
Origin of uropygial gland
First recorded in 1865–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for uropygial gland
a gland, situated at the base of the tail in most birds, that secretes oil used in preening
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012