Gape meaning : An act of gaping; a yawn. A large opening. A disease in poultry caused by gapeworm in the windpipe, a symptom of which is frequent gaping. The width of an opening. The maximum opening of the mouth (of a bird, fish, etc.) when it is open. To open the mouth wide, especially involuntarily, as in a yawn, anger, or surprise. To stare in wonder. To open wide; to display a gap. Of a cat: to open the passage to the vomeronasal organ, analogous to the flehming in other animals.