Main entry: effective, effectual, efficacious
Definition: producing or capable of producing an intended result or having a striking effect
Usage: an air-cooled motor was more effective than a witch's broomstick for rapid long-distance transportation-LewisMumford; effective teaching methods; effective steps toward peace; made an effective entrance; his complaint proved to be effectual in bringing action; an efficacious law
Antonyms: uneffective, ineffective, ineffectual
Definition: not producing an intended effect
Antonyms: unimpressive
Definition: not capable of impressing
Main entry: effectual, sound, legal
Definition: having legal efficacy or force
Usage: a sound title to the property
Antonyms: invalid
Definition: having no cogency or legal force