The phrase comes from the word Ã¢ÂÂmirthÃ¢ÂÂ, meaning happiness, joy or pleasure, when also combined with Ã¢ÂÂrocketÃ¢ÂÂ. Mirth rocket directly translates to Ã¢ÂÂpleasure rocketÃ¢ÂÂ which can be interpreted as a slang word for the erect penis.
Another word for the male genitalia, penis, cock, or shlong. Refereeing specifically to the penis when fully erect.
Hey baby, you want to get some dong bags and hop on the ole mirth rocket.