The phrase "haddest a go at" is rooted in colloquial English and means to attempt, try or undertake a particular action. Its antonyms would be words that express the opposite meaning such as "avoid," "refrain," "give up," "abstain," "fail," "neglect," "forsake," and "ignore." Interestingly, contrasting words like "achieve," "succeed," "accomplish," "win," "attain," "triumph," and "gain" would not necessarily be antonyms to "haddest a go at," as they do not indicate the avoidance or failure to attempt an action. It is important to understand the context in which the phrase is used to determine suitable antonyms that communicate the opposite intention.