Functional and Inefficacious

Opposite meaning words

Functional adjective - Being in effective operation.

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Inefficacious is an antonym for functional.

Inefficacious adjective - Producing no results.

Usage example: an inefficacious medication for a rare form of tuberculosis

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Functional is an antonym for inefficacious.

Cite this Source

Inefficacious and Functional. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/functional/inefficacious

Functional & Inefficacious. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/functional/inefficacious>.

Inefficacious or Functional. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/functional/inefficacious.

Google Ngram Viewer shows how "functional" and "inefficacious" have occurred on timeline