Taking a shit in the upper bowl of someone's toilet, such that the shit is not moved to the sewer when the toilet is flushed. The result is rotting shit in the top bowl of the toilet.
I topsided Dave when I was over at his house last night.
by eMeS September 11, 2004
Being on the topside of a boat or ship.
“Hey Dave! You should come out. We’ve been topsiding all day and it’s beautiful!”
by xmeekx December 17, 2013