An adjective used to describe something or something who is average or slightly below average. The best way to describe mid is a 4/10. This applies to people, food, music, style, and really anything else whatsoever.
Person 1: Hey what do you think of the new movie that just came out?
Person 2: it was mid, I’d give it a solid 4
When something is average or slightly not liked by the person.
Person 1: Have you seen One Piece?
Person 2: What? You mean Mid Piece?
Did you Listen to Certified Boy Lover Yesterday?
No it's Mid