Usually used by young men with low self esteem on social media in an attempt to “neg” attractive girls. This is done in hopes that they might undermine the self-confidence of a woman over time so she might be more vulnerable to your advances.
A person's opinion that is not valid in the writer's eyes.
This can also be used on people (Possibly to say they r no lifes)
Example 1: So.. You say Sugar x Ella is a valid Total Drama ship? That is so mid!
Example 2: ngl Jellybean is mid. - Meowbahh, not knowing she is also mid.