look up any word, like blumpkin:
 
1.
a scale or measurement used to measure how much fun one's having or had. zeero being no fun and splendid being the most fun ever.
OMG!! bro! we so much fun yesterday the funometer needle was reading Splendid
by otinga April 09, 2010
 
2.
the way you rate how much fun you're having with whatever you may doing at that moment
i am having so much fun chillin with my peeps that my fun-o-meter is going ding-ding-ding!!
by Deezee March 17, 2006