Meaning of the word inefficacy in English

What does inefficacy mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

inefficacy

US /ɪnˈef.ə.kə.si/
UK /ɪnˈef.ɪ.kə.si/

Noun

lack of power to produce a desired effect; ineffectiveness

Example:
The inefficacy of the old policies led to widespread public dissatisfaction.
Researchers are studying the inefficacy of the drug in certain patient groups.