Happens after you clog a toilet with a serious dump. As the bowl overflows, there is one little floater that stays inside the bowl and rides around the rim as the water still swirls from the prior flush.

(noun) A successful type of theft which results in an acceptable, impressive and rewarding payday for the protagonist.

Rim Rider "Jacob" is a moron sometimes and never agrees to one thing and was confirmed gay by BuzzFeed and Tan from Buzzfeed and is not goated on the sticks and is gay

A "Bed Event" where a man takes the hard "mushroom cap" of his penis and runs it across and around the rim of a girl's pukered anus but not to penetrate. Therefore rim riding has commensed.

1)A person who enjoys the pleasure of being anally invaded. (Also cockjockey)

2)A person who is not highly regarded in your opinion

A rim rider is the absolute pinnacle of faggotry, referring to someone who is not only a faggot, but a faggot's faggot.
This person has achieved such peak levels of faggotry that they are in fact incapable of sexual acts involving a penis, instead having to press assholes with another man, bouncing up and down, or "Rim Riding".