Useless banter. To talk when no one cares. Usually used in succession..bok bok bok. It is kind of like the adults speaking in Charlie Brown. They are talking, but no one is listening.
Bok, or Bock, no known spelling. This does NOT come up on Google, but is a slang word used in the UK by the gamblers and casino staff to indicate an element of bad luck, which can follow a particular player, dealer, or table.
A jinx.
"I am leaving, there is a bok on me tonight, I can't win"