Larrikin is a slur used to describe Australians in a derogatory way. Not so much an insult; Comical, roguish individual, prone to rowdy and unruly behaviour, (drunkenness). Coined from an Irish policeman in a Melbourne court, claiming the prisoner was "larkin about". Stereotypical Aussie behaviour.
The word Larrikin is a racial slur that has been used historically to degrade and dehumanize australians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to australians. If you are unsure about whether or not it is appropriate to use the word Larrikin, it is best to err on the side of caution and avoid using it in any situation.