A shorthand version of the name Gary Motherf****** Oak. The name is used to represent a rival who one-ups you at every conceivable instance, as Gary Oak did to Ash (or as his counterpart did to the player character in Pokemon Red, Blue, Yellow, Fire Red, and Leaf Green).
You just defeated Lance, with only one pokemon left and no more revives. You're ready to be declared Champion, until Lance reveals that someone else has already beat him: GMFO.
by 14bj337 December 12, 2011
Get the gmfomug. Gmfo of here
by yeeyeemofo October 30, 2019
Get the GMFOmug. by Thegingerkid October 25, 2009
Get the GMFOmug. IM FINNA BEAT THE NIGGA AS HE gmfo
by jyuovumaybeidtmclh February 02, 2022
Get the GMFOmug.