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inefficacious

Definitions of inefficacious
  1. adjective
    lacking the power to produce a desired effect
    “laws that are inefficacious in stopping crime”
    Synonyms:
    ineffective, ineffectual, uneffective
    not producing an intended effect
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    Antonyms:
    efficacious
    marked by qualities giving the power to produce an intended effect
    effective, effectual, efficacious
    producing or capable of producing an intended result or having a striking effect
    effective
    works well as a means or remedy
    show more antonyms...
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