inefficacy Meaning, Definition & Usage

  1. noun a lack of efficacy
    inefficaciousness.

WordNet

In*ef"fi*ca*cy noun
Etymology
L. inefficacia. See In- not, and Efficacy.
Definitions
  1. Want of power to produce the desired or proper effect; inefficiency; ineffectualness; futility; uselessness; fruitlessness; as, the inefficacy of medicines or means.
    The seeming inefficacy of censures. Bp. Hall.
    The inefficacy was soon proved, like that of many similar medicines. James Gregory.

Webster 1913