Slang for the word "Gone"; Becoming completely intoxicated, or "Getting Gone" (G1). G1 is often changed to G2, G3, G4 or even up to G5, to refer to the level of "Gone" (G1), much in the same way the Enhanced Fujita Scale measures tornadoes. In parts of the Southern US, a "boah" is often added to a sentence to enhance G1.
G1 stands for generation 1 for the Transformers lore which stands for the G1 continuity family which consists of the 1980s cartoon, the original marvel comics, the g2 comic, the g1 Dreamwave comics, and the IDW comics People who do not know how lore works will incorrectly use the tern "gen 1" which is specifically for the pokemon fandom, so next time you say Gen 1 for Transformers please swallow a bullet. Booty