On the button
Did "on the button" originate from the curling term "button"?
That's a plausible notion. The game is old, although I don't know when players started calling the centre of the target the button. Early newspaper citations of 'on the button' mainly relate to boxing, i.e. 'on the chin'. As yet, I've not been able to find any documented link between 'on the button' and curling.