Definitions by Cheesepack92

Yelpgasm 

That feeling you get right as you're about to fall asleep, where you feel as if you are falling, so you jerk yourself awake while making a yelping sound combined with the sensation of spontaneous orgasm.

Right as Megan was about to fall asleep, she suddenly jerked awake and experienced a yelpgasm due to the sudden excitement.

Yelpgasm by Cheesepack92 November 16, 2009