one pound coin

From an old anti smoking advert
How things are usually done

Someone who is not all there / someone with mental issues / someone who may be a bit slow / someone who is an idiot

doing anything as fast as you can
Feeling really sick
Movies, Cinema - e.g. "Want to come to the pictures?"
God no - e.g. "Gad's no!"

"I dont believe you!"


but not necessarily calling someone a lier, can also be said in a state of shock.