Dokov is a verb similar to the verb fail. It is used when someone has made a huge mishap or has failed really badly in doing something. It can be used in a number of occasions, for instance: Don't be so dokov - dont fail so much in life; Don't dokov on me now man - dont fail me, do not bail on me.
Don't be so dokov - dont fail so much in life
Man dont go dokov on your exams - dont fail the exams and than retake them and fail again