Someone who plays a multiplayer video game and refuses to use any weapons/characters/skills that aren't considered "
meta."
Although someone who uses the meta can be someone who simply enjoys using the most reliable tactics available, "Metaslave" is used to describe someone who sees anyone who doesn't use the meta as an idiot or noob and may even
berate those who refuse to
comply with their demands.
Originated from League of Legends to describe someone who uses an overpowered champion in order to climb up the competitive ranks.
"Hey, why did Todd get banned from the community server?"
"He kept yelling at this dude for using a
machine gun instead of an
SMG. He was
promptly called a Metaslave then perma-banned."