Goo Share definition Flag A state of euphoria. Some say this phrase is from a porno, some say it is the goonies. Use it wisely. Bryan: Who is that? Evan: Lindsay Lohan Bryan: Goo! Goo by KillACommyForMommy April 11, 2005 0 0 Get merch Get the Goo mug. Buy Now — $32.95 See more merch