1. successful in producing a desired or intended result; effective
Usage: formal

Examples

• The new medicine proved efficacious in treating the infection.
• Her efficacious leadership style helped the team meet all their goals.
• The study showed that the treatment was highly efficacious for most patients.
• Traditional remedies can be surprisingly efficacious for certain ailments.
• The company’s efficacious marketing campaign doubled their sales.
• Scientists are searching for more efficacious methods of renewable energy production.