The phrase "having whack" is a colloquial term that means being intoxicated or high on drugs. This phrase may not be appropriate or accepted in certain contexts, so it is useful to know some synonyms that can be used instead. Some of the common synonyms for "having whack" include being under the influence, being intoxicated, being buzzed, being stoned, being high, being inebriated, being tipsy, being plastered, being wasted, and being loaded. Using these alternative phrases may help you avoid using offensive or inappropriate language and more effectively communicate with others in a variety of settings.