(n.) Want of power to produce the desired or proper effect; inefficiency; ineffectualness; futility; uselessness; fruitlessness; as, the inefficacy of medicines or means.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). inefficacy. Retrieved September 24, 2026, from http://smartdefine.org/inefficacy/definitions/2021133 |
| Chicago | Webster's. 2011. "inefficacy" http://smartdefine.org/inefficacy/definitions/2021133 (accessed September 24, 2026). |
| Harvard | Webster's 2011, inefficacy, Smart Define, viewed 24 September, 2026, <http://smartdefine.org/inefficacy/definitions/2021133>. |
| MLA | Webster's. "inefficacy" 27 May 2011. Web. 24 September 2026. <http://smartdefine.org/inefficacy/definitions/2021133> |