A flake is someone who generally makes plans with you, promises to do things with you but can never seem to follow through. When confronted with their behavior they usually get defensive and run away.
Jordan made plans to go hangoutwith me. He either never shows up or is super late. Jordan is a flake.
Flake mean don’t like, they face not good around you, or moving weird. Like if you see a car riding thru da same hood bout 3 times you gon call that car “flake”