Silly?
Posted by Rube on April 08, 2004
In Reply to: Goon it up posted by Bruce Kahl on April 05, 2004
"Hearing this phrase, I would say it means to act silly."
I have no counter theory to offer, but since "goon" is always a perjorative, meaning a large nasty person, I fail to see how "gooning it up" couold mean being silly.