To make a face similar to that of 2000AD's comic book hero 'Judge Dredd' in response to any situation where you feel it is appropriate.
Can also be sent via text messages with the emoticon "XC".
Dave: "I was so tired this morning I poured gone off, lumpy milk in my coffee and took a massive swig."
Simon: "Eurgh! What happened?"
Dave: "It gave me Dreddface."
Eve: "Walkers should change the colour of the cheese and onion crisp packet back to green, and salt and vinegar back to blue!"
Jack: "No, you're wrong! You're all kinds of wrong!"