useless or futile
WordReference Random House Learner's Dictionary of American English © 2025
un•a•vail•ing /ˌʌnəˈveɪlɪŋ/USA pronunciation
adj.
WordReference Random House Unabridged Dictionary of American English © 2025- having no effect;
futile:unavailing efforts.
un•a•vail•ing
(un′ə vā′ling),USA pronunciation adj.
un′a•vail′ing•ly, adv.
- ineffectual;
futile.
- un-1 + avail + -ing2 1660–70
Collins Concise English Dictionary © HarperCollins Publishers::
'unavailing' also found in these entries (note: many are not synonyms or translations):