Definition of "zonko"

" […] A sister of Joseph Gerard […] was found unconscious on the kitchen floor by the family cook early this morning. […] " […] What leads could they have, if the old lady was el zonko?

2007, Richard Bachman, Blaze, page 125

" […] To maximise your recovery time I am forced to apply a sedative." […] Think for about three seconds. Then I'm zonko.

2011, John Trevillian, The A-Men Return