See Also: efficacious(dictionary)
efficacious(dictionary)

efficacious (iou)



efficacious adjective. E16.
[from Latin efficac-, efficax, from efficere: see EFFECT noun, -ACIOUS.]
That does or is certain to produce the intended effect; effective.
P. Medawar At present there is no convincing evidence that psychoanalytic treatment as such is efficacious.
efficaciously adverb M17.
efficaciousness noun M17.