Inefficacious and Invalid

Inefficacious

Inefficacious adjective - Not producing the desired result.

Invalid and inefficacious are semantically related. In some cases you can use "Invalid" instead an adjective "Inefficacious".

Invalid

Invalid adjective - Chronically or repeatedly suffering from poor health.

Inefficacious and invalid are semantically related. Sometimes you can use "Inefficacious" instead an adjective "Invalid".

Cite this Source
Invalid and Inefficacious. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/inefficacious/invalid
Inefficacious & Invalid. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/inefficacious/invalid>.
Invalid or Inefficacious. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/inefficacious/invalid.
Google Ngram Viewer shows how "inefficacious" and "invalid" have occurred on timeline