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

— in·ef·fi·ca·cious·ly adverb

— in·ef·fi·ca·cious·ness noun

1658

Synonyms: counterproductive, feckless, hamstrung, ineffectual, ineffective, inefficient, inexpedient

Antonyms: effective, effectual, efficacious, efficient, expedient, operant, ultraefficient

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