Efficacy
/ˈɛf.ɪ.kə.si/noun
The ability to produce a desired or intended result.
Did you know?The concept of efficacy has deep roots in alchemical traditions, where the effectiveness of a potion was believed to be linked to the alignment of celestial bodies.
Etymological Timeline
Proto-Indo-European
PIE
*dʰe-
“to put, to place, to do.”
Latin
Latin
efficax
“effective, capable of producing a desired effect.”
Medieval Latin
Medieval Latin
efficacia
“the quality of being effective.”
16th Century
English
efficacy
“the power to produce a desired result, adopted from Latin.”