Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps


Noun: efficacy  e-fu-ku-see
  1. Capacity or power to produce a desired effect
    "concern about the safety and efficacy of the vaccine";
    - efficaciousness

Derived forms: efficacies

See also: efficacious, inefficacious

Type of: effectiveness, effectivity, effectuality, effectualness

Encyclopedia: Efficacy

Nearest

effervesce
effervescence
effervescent
effervescing
effete
effetely
effeteness
efficacious
efficaciously
efficaciousness
efficacy
efficiency
efficiency apartment
efficiency engineer
efficiency expert
efficient
efficiently
effigy
effing
effleurage
effloresce