australian slang. a simple but effective insult, referring to someone who is severely intellectually deficient, with often the additional connotation of also being a
bum,
bogan, eshay or similar. like an extreme version of a
doofus.
words such as “cunt” (a more mild use) or “dog” (a more hurtful and aggressive use) can follow for emphasis, as “gronk cunt” or “gronk dog”, the latter of which is usually uttered minutes before a fight ensues, between (often under the influence of
drugs or alcohol) bogans or eshays of no particular age demographic.