Definition of "bok"

And he says, "Chicken! Bok bok bok bok!" One time I got up and put the controller down and we started fighting.

2000, William S Pollack, Todd Shuster, Real boys' voices

So the librarian gives the chicken a book. The chicken goes away, but comes back the next day, goes up to the librarian's desk and says: 'Bok, bok!'

2004, Andrew Bennett, Nicholas Royle, An introduction to literature, criticism and theory