a person who has been hyper from being extremely happy and is crashing from using too much energy at once. This person will be extremely tired and wontwant to do much afterwards. (this is why you onlywant to catch someone entering the phase of hyber-happyiness so that you can have fun, not after.)
"dude that guy's been running around in circles all day"
"yeah but I think he's done now wait....for.... it..."
"yup, he's done for now. Just falling on the ground like that he must be hyber-happy-tired!"