What is Just No?
1.
1. an expression of mild shock or disgust.
2. said in a less assertive manner it can be used when you can't be bothered to say anything else.
1. person a, "I think I might be tempted to put marmite on this pizza, and then rub it on my face."
person b, "Just no."
2. person a, "Do you think that global warming is having a cumulitave effect on the way we are living today, or that media hype is exadurating the situation?"
person b, "Just no."
See