To be sodomized by an exceptionally large penis. Portmanteau of "back doored," a slang description for anal sex, and "Shaq," the nickname of a former NBA player rumored to have an exceptionally large penis.
I got Shaq-doored in the alley by my Shaq-foo instructor after class, and now my asshole feels like I sat on a Shaqtus.
by Bobert, but I go by Rob January 14, 2020