That's really interesting Jos. To 'conk' means to bash, and conk also means ones nose. Years ago, the playground was swarming with conker players swinging away with their prize conkers. Some had boiled them in vinegar to harden them (cheats!) and if ones conker had smashed six others it was called a 'sixer' and so on.
Such a shame that this traditional, seasonal game is now banned. I don't remember any child being injured in the past.