efficaciousness

English

Etymology

From efficacious +‎ -ness.

Noun

efficaciousness (uncountable)

1. Quality of being efficacious.
   • 1961, Harry E. Wedeck, Dictionary of Aphrodisiacs, New York: The Citadel Press, page 216:

     In ancient mythology, the efficaciousness of the satyrion is attested, particularly in the case of Hercules.