D defs.my
Entry 1 sense Webster, 1913

Inefficacy

· In·ef·fi·ca·cy · IPA
01 n. Lack of power to produce the desired or proper effect; inefficiency; ineffectualness; futility; uselessness; fruitlessness; as, the ineffic…
  1. 1.
    Lack 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.