inefficacious

adjective
in·​ef·​fi·​ca·​cious | \(ˌ)i-ˌne-fə-ˈkā-shəs \

Definition of inefficacious 

: lacking the power to produce a desired effect : ineffective

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Other Words from inefficacious

inefficaciously adverb
inefficaciousness noun

Examples of inefficacious in a Sentence

his efforts to restore the neglected houseplant back to health were belated and sadly inefficacious an inefficacious medication for a rare form of tuberculosis

First Known Use of inefficacious

1658, in the meaning defined above

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Time Traveler for inefficacious

The first known use of inefficacious was in 1658

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