useful Antonyms

useless unavailable venenate vandalic valueless vain superfluous unvaluable untreatable unsignificant vesicant wicked junky unavailing unprofitable unnecessary irrelevant unsuitable unimportant wrackful worthless unmeaning unfavorable troublesome resultless renitent pyrrhic purposeless purportless profitless privative prejudicial rewardless ruinous shocking supplementary supplanter supernumerary successless succedaneum sleeveless slanderous sisyphean poisonous bunglesome bad at unedifying un-come-at-able unattainable unachievable