efficace

Efficace is an adjective used in Italian and French to describe something that produces the intended result or has a strong effect. In Italian it commonly describes actions, methods, medicines, policies, and performances: un metodo efficace, un farmaco efficace. In French the same sense applies: une mesure efficace, un traitement efficace. In both languages, the term emphasizes effectiveness rather than speed, though in practice it can imply practical success in real-world use. The word forms differ by language: Italian uses efficace in the singular for both genders and efficaci in the plural; French uses efficace in the singular for both genders and efficaces in the plural.

Etymology traces efficace to Latin efficax, from efficere, meaning “to accomplish, to bring about.” The Latin root combines ex- “out” or “thoroughly” with facere “to do.” The French development passed through Old French, while Italian adopted a form descended from Latin as well. In Italian and French the word functions as a standard adjective, with concord governed by gender and number in each language.

Usage notes and nuance: in medicine and science, the related noun forms efficiency or efficacy convey the degree to which a treatment or procedure achieves desired outcomes under specified conditions (efficacia in Italian, efficacité in French, efficacy in English). In everyday language, efficacious descriptions refer to real-world effectiveness rather than mere potential. Antonyms include inefficace in both languages. Related terms include efficient/effective synonyms and, in Italian, l’adjective efficiente to emphasize resource-oriented efficiency.