✅

efficacious

adjective

/ˌɛf.ɪˈkeɪ.ʃəs/

Meaning

Successful in producing a desired or intended result; effective.

Effective for a specific purpose

The vaccine proved highly efficacious in preventing infections.

This medicine is highly efficacious in treating headaches.

effective, potent, successful, Effective, Productive, Efficient

Entry 1

effective, potent, successful

Entry 2

Effective, Productive, Efficient

ineffective, inefficient, futile, Ineffective, Useless, Inefficient

Entry 1

ineffective, inefficient, futile

Entry 2

Ineffective, Useless, Inefficient

Having or showing good manners; properly raised.

excessive; inappropriate; more than is necessary or proper

lacking happiness or comfort; gloomy; depressing; without cheer

Extremely beautiful or attractive.

Involving or causing a complete or dramatic change; radically new or innovative.

Rude in a mean-spirited and surly way.