efficaciousness en · NOUN
Etymology
From efficacious + -ness.
Meanings
-
(uncountable) Quality of being efficacious; efficacy.
In ancient mythology, the efficaciousness of the satyrion is attested, particularly in the case of Hercules.
1961, Harry E. Wedeck, Dictionary of Aphrodisiacs, New York: The Citadel Press, page 216: