...From The Merriam-Webster Dictionary

Exhaust-
noun 1- To use up wholly
2- To tire or wear out
3- To draw off or let out completely
4- empty

Exhaustion-
noun - Extreme weariness, fatigue

Hmm...

I think it's funny how exhibitionism was just a few words down. Funny how some words are so close to one another but are so completely different.