Yawn
Part of speech: noun
Definition: The action of yawning; opening the mouth widely and taking a long, rather deep breath, often because one is tired.
Part of speech: verb
Definition: To open the mouth widely and take a long, rather deep breath, often because one is tired and sometimes accompanied by pandiculation. To present an opening that appears able to swallow one up, literally or metaphorically:
Example sentence: I have several close friends who are insomniacs. Over the years, I've heard their stories about being up in the middle of the night, completely awake. I see them yawn at 11 A.M. and know that, regardless of what they are doing, they'd probably rather be in bed sleeping. I've always had sympathy for them, but I've never really understood it.
Gape
Part of speech: verb
Definition: To open the mouth wide.
Part of speech: noun
Definition: An act of gaping; a yawn.