The Brief: Normies are people who are in the mainstream and out of the loop.

DEEP DIVE
Normies are normal people who do not know about alternative, emo, queer, meme, and other niche communities. People who are part of these communities often criticize normies for trying to infiltrate subcultures to seem quirky and knowledgeable.
kinda upset that the “this post was made by ____ gang” has now reached the normies
— Lucidityy (@YTLucidityy) October 22, 2018
Normies ruined the odd flex joke
— numbah 69 (@owaridank) October 12, 2018