When someone makes a comeback so epic, it gives all Canadians orgasms, if you know what I mean. Furthermore, the wave of awesome coming from the comeback itself is so powerful it leaves the offended and the audience speechless, making grounds for the offender to yell the word. Originated when Agent FD killed all the zombies of LA by using slips of the tongue.
Fourth Drink: "Your face!"
Person B: "..."
Fourth Drink: "I fourthed you like maple syrup on spaghetti!"