There are 2 results of your search for bocka1.
bocka1
haircut: You've had a bocka! Also, bocker.
Contributor's comments: This word means "short" haircut in Bacchus Marsh (Vic). I have not met anyone outside Bacchus Marsh who knew what it means.
Contributor's comments: In my 47 years of living in Melbourne have never heard the word 'bocka' used for a hair cut.
Contributor's comments: A haircut. Usually/exclusively [used in the] past tense: "I see you've had a bocker" or "nice bocker, mate" but rarely/never "I'm going to get a bocker."
Contributor's comments: In Warracknabeal we used bokka to refer to a type of haircut.
bocka2
A bocka was a punch to the upper arm, inflicted as punishment by a peer for minor misdemeanours at school. Also, bokka.
Contributor's comments: to punch someone on upper arm with knuckle to make limb stiff or produce bruise: "Sir, Jones just gave me a bokka."
Contributor's comments: At secondary school in Melbourne in the 1950s this was the word used for a sharp blow (typically inflicted with a knuckle) to the outer side of the upper arm, about level with the top of the bicep. I have no idea how it was meant to be spelled, as we never wrote it down.
Contributor's comments: I know of someone from the Mallee Wimmera region who would say 'no bokkas' after flatulating, to ensure that no-one would punch him in the arm after the act.