When a student in your class tries to be funny but the teacher picks up to what he or she is doing and they get yelled at and sent out of the room and just hear a random "NO SCOPE!!" Out of nowhere.
Ok class do you all have your project done that was due today? (Random student) No but I sure got DEEZ NUTZ!! Teacher- Leave the room now we're going to call your parents! (Random student) NO SCOPE!!!
A video game term. This is a skill that very few gamers can pull off, due to the inability to see the crosshairs on a sniper rifle without looking down the scope. You have to be very quick and confident to pull it off, otherwise, you look like a desperate noob.
"Wait, what just happened?!"
"I think you got No Scoped."
"That guy must be a real stud."