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adj. Not availing; ineffectual or useless. See Synonyms at futile.

adj. useless, fruitless, futile

Not availing or having the effect desired; ineffectual; useless; vain: as, unavailing efforts; unavailing prayers.

adj. producing no result or effect

"He was not, however, a man to waste, in unavailing regrets, hours that might be more advantageously employed to repair the evil, and he therefore at once set about the arrangement of measures for inducing and enabling the banks to resume at the earliest possible moment."

useless   

ineffectual    futile   

ailing    assailing    bailing    baling    curtailing   

fruitless    ineffectual    impotent    abortive    inapplicable