Gaping open; cavernous: a yawning abyss. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "yawning" in a sentence
"I'm disgusted at how marginalized people are, she added, referring to what she described as the yawning gap between the very rich and everyone else."
"Finally, yawning is "contagious" and has a high rate of suggestibility — so choose your company carefully."
"Vanya enters, yawning from a nap, the three complain about how all order has been disrupted since the professor and his wife, Yelena, arrived."