Definitions by David McReece

Gorilla joy 

The feeling of joy experienced by two or more siblings when they first see each other again having been separated for an extended period of time (usually at least two years). Can apply to both forcible and voluntary separation. May also be referred to as "Gorilla happiness," an almost identical emotion.

Oh, look at those two, they are so happy to see each other again. What gorilla joy!

Gorilla joy by David McReece August 16, 2012