A normie is a person who has no special trait that makes them 'unique'. A normie can be identified if they repeat a dead meme so many times it because cancer, or if you see someone posting about their wins on Fortnie on Snapchat or Instagram.
Normie: Do you know de way, doge doge doge, I have 9 solo wins on Fortnite!
Not a Normie: You wanna see how many times I can beat him before he dies?
A normal, and/or mainstream person, typically referring to someone who is ignorant about a specific topic/subculture you're adept in.
Originally used by memelords to refer to those who haven't embraced a meme or meme culture (Also called, "Normalfags"), though can be used in reference to other topics as well, and is commonly used outside of meme culture. Can refer to anyone who is outside of your specific subculture.
"That normie doesn't even know what pepe is. What a fuckingnormalfag."
"She doesn't know what Kappa is? Normie. Must not use twitch."