efficacy
efficacy Lexical Profile
efficacy Game Scores & Validity
• noun
The ability or capacity to produce a desired or intended result, especially under controlled or ideal conditions.
"Researchers conducted a three-year clinical trial to evaluate the long-term efficacy of the new vaccine."
Word Nuance & Usage
In clinical and academic contexts, 'efficacy' specifically denotes how well an intervention performs under ideal, controlled conditions (such as a clinical trial), whereas 'effectiveness' measures how well it performs in real-world practice; it should also be distinguished from 'efficiency', which refers to achieving a result with minimal wasted effort or expense.
• Rhymes for efficacy
• Nearby Words
Word Origin & Etymology
Borrowed in the early 16th century from Latin efficacia, derived from efficax ('powerful, effectual'), from the verb efficere ('to accomplish, work out'), combining ex- ('out') and facere ('to make, do').