I wore my cape in a futile attempt to keep dry
useless, worthless, ineffectual, ineffective, inefficacious, to no effect, of no use, in vain, to no avail, unavailing;
hopeless, doomed, lost
Australian/New Zealand informal no good to gundy
[Antonyms] useful, fruitful
Choose the right word
futile, fruitless, vain, pointless
These words all describe unsuccessful undertakings, but some refer to the prospects of success, some to the outcome, and some can refer to either.A futile undertaking has no chance of success, which may or may not be recognized by the person embarking on it ( it would be futile to argue | the Bank of England threw away £10 billion in a futile attempt to prop up sterling).Fruitless is most commonly used to describe an undertaking that turns out unsuccessfully ( an aerial search of the area proved fruitless, and the men were presumed dead | talks collapsed after months of fruitless negotiation).Vain is a more literary word, which can refer either to the prospects of success ( I pulled the blankets over my head in a vain attempt to shut out the ugly visions) or the result, usually in the phrase in vain ( after I had waited in vain for six months, I lost hope).Pointless describes something that serves no useful purpose ( pointless committee meetings), so is used to convey the lack of any prospect of success, which should be obvious to the person contemplating the action ( I knew it would be pointless expecting him to change his mind).