noun (used with a singular verb)
Veterinary Pathology. a parasitic disease of poultry and other birds, characterized by frequent gaping due to infestation of the trachea and bronchi with gapeworms.
a fit of yawning.
Origin of gapes
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
noun (functioning as singular)
a disease of young domestic fowl, characterized by gaping or gasping for breath and caused by parasitic worms (gapeworms)
informal a fit of yawning
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