G4

Initialism of Generation Four.

(technology) the PowerPC G4 microprocessors produced by Apple.

(politics) Initialism of Group Four (“G4 nations, Brazil, Germany, India, and Japan, who support each other's attempts to secure a seat at the United Nations Security Council”).

(fandom slang) Initialism of Generation Four (“the fourth generation of the "My Little Pony" toy franchise, known as "Friendship is Magic"”).