unavailing
1. [ adjective ] producing no result or effect
Synonyms: futile otiose ineffectual
Examples:

"a futile effort" "the therapy was ineffectual" "an otiose undertaking" "an unavailing attempt"

Related terms: useless
Similar spelling:   unveiling
  unfailing
  unfailingly
  unavailable
  unfeeling
  unhappily
  unfeelingly
  unfaltering