efficacy
/ˈɛf.ɪ.kə.si/ noun C2- The ability to produce a desired effect under ideal testing conditions.
- A degree of ability to produce a desired effect; effectiveness.
Plural efficacies
From the library
I wonder who first discovered the efficacy of poetry in driving away love!”
Philosophers may well say, and practical men will always support the opinion, that money mitigates many trials; and if you admit the efficacy of this sovereign balm, you ought to be very easily consoled—you, the king of finance, the focus of immeasurable power.”
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