Synonyms of the word 
INEFFICACIOUS → INEFFECTIVE - INEFFECTUAL
inefficacious
- adj. Incapable of having the intended consequence.
- adj. Not effective.
ineffective
- adj. not having the desired effect; ineffectual.
- adj. lacking in ability; incompetent or inadequate.
ineffectual
- adj. unable or insufficient to produce effect; futile.
- adj. worthless.
- adj. weak, indecisive; lacking forcefulness.
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