Where does “efficacy” come from?
Efficacy comes from Old French efficace, derived from Late Latin efficacia and Latin efficax, meaning "powerful" or "effectual," ultimately from Latin facio meaning "to do" with the prefix ex-.
efficacy (English): Ability to produce a desired effect under ideal...
Definitions
- Ability to produce a desired effect under ideal...
Ancestry of “efficacy”, step by step
Words derived from “efficacy”