a person who is naturally very poor at something:
2. puncist (noun)
a person who purposefully and deliberately does something poorly, but is actually good at it:
the act of deliberately doing something poorly:
2. "British star Les Dawson was an accompished pianist, but had a comedy performance of hitting incorrect notes. He was a puncist"
3. "Johnny was puncing about at playing pool so he could hustle for bigger money"
2) I made your friend annoyed enough to go home just from calling him/her a punce, I guess I was right.
3) We were moving bricks all day, I was lifting ten at a time but my friend could only manage four at a time, such a punce.