Sluggy Share definition Flag a freakishly small penis, with little or no shaft and a very small helmet. Men usually get a "Sluggy" after taking extasy. "once he had taken his pants off i saw he had a sluggy and i immediately asked him to leave" Sluggy by joshypl June 9, 2008 0 0 Get merch Get the Sluggy mug. Buy Now — $32.95 See more merch